Following are speculations for Season 4:

Season 4
40S. Time Crash. A Children in Need Special starring Peter Davison as the 5th Doctor and David Tennant as the 10th Doctor.
161107 Approx. 7 minutes
Special by Steven Moffat
Two Tardises crash in the vortex and the 10th Doctor finds himself face to face with the 5th Doctor. They must avert a hole in the space time continuum the size of Belgium.

40X. Voyage of the Damned
192. 251207 - 40X 1h Christmas Special by Russell T Davies
A vague connection to Kaldor City and the Robots of Death. The Titanic crashes into the TARDIS just as it is dematerialising. The Doctor goes on board to find it is an interstellar luxury liner in the shape of the Titanic and full of Hosts, droids programmed to kill, kill, kill. Can the Doctor stop the ship from exploding and destroying the Earth? Starring Kylie Minogue as the Doctor's companion Astrid Perth.

402. The Fires of Pompeii
194. 120408 by James Moran
What has ancient Rome got to do with anything? A quick trip to Pompei with only hours before Mount Vesuvius is about to explode. Donna wants to save a family but the Doctor doesn't. And how did Donna end up as a sacrifice? Rock monsters everywhere. Russell says that the monsters in this episode are the most ambitious to date. A dark depressing episode.

403. Planet of the Ood
195. 190408 by Keith Temple
A trip to the 42nd century to the Ood's home planet. We find they're really slaves. The Doctor has to find a way to free them, but the Ood have had their own plans for 200 years. We find out what really happened to them to have caused them want to serve.

404. The Sontaran Strategem
405. The Poison Sky
196. 260408 by Helen Raynor
        030508 
Martha contacts on her mobile phone while working at UNIT. (Bring back the Brigadier!) and asks him to help fight a Sontaran invasion, before being captured by the Sontarans. (Bring Back The Brigadier!) The Sontarans activate their atmosphere changing device and increase global warming dramatically. UNIT can't do anything about it  (BRING BACK THE BRIGADIER!!!) and the Doctor has to make a sacrifice.



406. The Doctor's Daughter
(For once, I guessed the title correctly!)
197  100508 by Stephen Greenhorn
The Doctor discovers a laboratory which has been experimenting with his DNA. They've used it to create something so shocking, so unimaginably evil that it will scare you to the root of your core, destroy your faith in the Whoniverse and give you nightmares for years to come. They create the Doctor's daughter. NB: He'll probably find out about this at a scientific establishment wearing his James Bond tuxedo.  There'll be lots of explosions and running around and probably a computer graphic monster or two. Think Alien 4 meets James Bond.

407. The Unicorn and the Wasp
198.170508 by Gareth Roberts
Donna and The Doctor visit Agatha Christie, played by Fenella Woolgar, and together they investigate a strange murder.


 
 
 
 
 
 
 

Turlough, oops, I mean Donna starts receiving strange images of a girl with blond hair. The girl's name is Rose and she warns Donna of a plan by the Daleks and an old enemy of the Doctor's to destroy her universe.

410. Midnight 
199. 070608 by Russell T Davies
Rose, Martha, Catherine and Sarah Jane band together to control the TARDIS and try to find the Doctor who gets himself lost in space! Captured by the Eternals, Daleks, Axons, Sontarans?

411. River's Run
412. War on Skaro
413. Journey's End
200. 140608 by Russell T Davies
        210608
        280608 
The Doctor finds out about the messages from Rose but can't do anything about it when suddenly the alternate reality holding Mickey, Jackie and Rose collapses, sending them back to their original universe. 

Confirmed that this final story will feature Rose, Mickey, Pete, Jackie, Sarah Jane, Captain Jack, Martha Jones and K9 as well as Donna and the Doctor. Gwen and Ianto from Torchwood also make a brief appearance. It'll also feature Davros played by Julian Bleach. It is likely to feature Sontarans and Daleks in a war as well as other aliens in a final gobsmacking battle.

Davros has been located by Caan and he is helping the Dalek to create a new race of Daleks. In a shock development in the final episode, a Dalek casing opens to reveal Harriet Jones, played by Penelope Wilton, the mother of all the new Daleks.

The Daleks have enslaved 21st century London, but which London?

Rumoured to feature the newly created daughter of the Doctor.

It's also possible the Master will be back in this episode, manipulating everything from behind the scenes, through Donna.

Somewhere in this story, the Doctor and co travel to an alternate future with the Daleks running the world and greenhouse gases at an all time high.

This would also be story number 200 as well as a story for the 45th anniversary so Russell will probably pull out all the stops.

The final scenes, revealed in released pictures awhile ago, suggest that the Doctor is involved in a freak explosion which splits him into two Doctors, and Sarah, Jack, Martha, Rose and Donna try to put him back together.

Final scene spoiler
Donna had been taken over by the Racnoss years ago and it has been slowly growing inside her. A Racnoss space ship appears but Donna is hit by a car and Wilf takes care of her but she's lost all her memories. Apparently the Doctor doesn't believe she would be able to live with herself if she knew what she had done. Not sure about the Racnoss spaceship thing, unless The Master took it.

This is believed to be a crash and burn story which wipes out almost anything that Russell T Davies has had a hand in creating in the past few years so that the new producer can start with a clean slate, so to speak.

Message for RTD. PLEASE PLEASE don't make any of these stories a global warming story. While most people on Earth think it's carbon causing the increasing temperature the Doctor would KNOW it is just the sun's solar cycle. If there's anything about carbon/global warming, please let it be the other characters who say it.

At least Stargate Atlantis included an off-the-cuff remark to confirm to viewers they were going to stick to the facts - "Rodney: This isn't some kind of cyclical climate change..."

40X2. The 7 Doctors (Suggested Title)
201 231108 By Terrance Dicks
Rumoured that an extra special story will be written for the 45th anniversary to be broadcast on the 23rd November 2008 starring Sylvester McCoy, Paul McGann, Peter Davison, Colin Baker, Tom Baker and David Tennant with special appearances by other guest actors (Eccleston?). Alternately this special may appear as a Children in Need extravaganza. With Peter Davison and Tom Baker confirming they would return for a cameo if asked, this is looking more and more likely. Fingers crossed!

50S Rose Tyler: Earth Defender:
       War Part 1 and Part 2
202 110409 by Russell T Davies
       290809
The 2 Doctor Who telemovie scripts have been completed and centre around Rose Tyler, Earth Defender, trying to track down the Doctor who's caused some problems in the past, which are affecting the present. Billie Piper returns. This article also says that several Hollywood names have been approached but have turned down the offer to play a major villain linking the 3 telemovies. Hugh Grant was recently approached to star as the villain. >

60X The End of Time
2009 Christmas Special
203. 251209 By Russell T Davies
At the end of the 2009 Christmas special David Tennant's 10th Doctor regenerates into Robert Carlyle as the 11th. Well, that's the plan. Robert is currently in negotiations.

Other notes for the 2009 season
Donna and Martha are not in season 9 as Martha will be full time on Torchwood and Donna turns out to be a bad character, like Turlough! (Possessed by something 'on her back' as in Sarah Jane Smith in Planet of the Spiders) She may leave in the Christmas Special

It's still rumoured that Jennifer Saunders appears as a temporary Doctor either in the Christmas Special or the Children in Need special. Remember what happened in the first Christmas special when the Doctor lost his hand? Well, other things can happen in that period!

2010 Series