Doctor Who : so what's next after the big series finale?

Well, the series finale had everything: two Doctors, old friends, old enemies - and even the return of tin can canine K9 to help save the day.

Plus, of course, those corny celebrations when Earth returned to its rightful place.

Not to mention Daleks talking in German ... sounding just like a bad wartime b-movie.

But it also posed big questions which will be answered in this year's new-look Torchwood, next year's specials and the fifth Dr Who series proper in 2010.

1. Will Martha and Mickey replace Owen and Tosh in the Torchwood team?
It's certainly convenient that they just happen to have two places to fill in that Cardiff basement.

2. Was Harriet Jones all she appeared to be?
The fan forums have been abuzz with suggestions that she had sinister Master-made motives and, of course, we never actually saw her die. Did you hear the drums, by the way?

3. Will the tough Doctor doppelganger, destroyer of planets, return from his parallel dimension to cause trouble for our hero further down the timeline?
It's surely too tempting a scenario to dismiss, and an excuse to bring Rose back, too.

4. Is Donna Noble coming back?
Catherine Tate says she's called it a day but did you see that ring she was wearing in her final scene? Could it have been the Master's ring of power, taken from his funeral pyre at the end of series three by an unknown female hand? If so, she could well regenerate, and a door has been left ajar.

5. Will the Daleks be back?
Of course they will, Davros conveniently disappeared in the smoke, and he's cheated death three times before. The official line from Russell T Davies is that you never write him off.

6. Who will take over from David Tennant when he quits the Tardis?
The favourite still seems to be Life On Mars star John Simm, who says he's keen to return to Dr Who after his show-stealing turn as The Master. Don't forget that missing ring folks!

7. What about Professor River Song, the mystery woman played by ER star Alex Kingston, who was left as a memory in the Library planet databank?
Word is that she'll be back as new series mastermind Steven Moffat tells the tale of the woman who may be (a) the Doctor's wife, (b) the Doctor himself after a future regeneration or (c) the spirit of the Tardis.

What did you think of the finale? And who should take over from Tennant in 2010? Post your views.