It made me feel just a tiny bit sick when I realised, and it's certainly making me feel a little bit sad and thought ful now. When it comes to the regen I will probably be in floods of tears because, I'm like that.... but I don't think it means the sky is falling.
Here's my thinking...
a) it was David Tennant in the role that made me start writing fanfic again, for one - a small reason, but a reason nonetheless. Writing fanfic again has kicked me into writing again, full stop. So maybe the change will become a signifier of a transition for me as to the focus of my writing.
b) It was DT who changed my relationship with Doctor Who - from the Doctor being a father/teacher figure to being an attractive, enigmatic 'lover/friend figure'. To an extent, it was Chris who started that change, and a lot of it is probably related to my age (although even young me crushed horribly on older guys - Inspector Morse, for a start) and life experiences. I don't know if overall that's a good thing or not, but it did happen.
c) David is a very good actor. I'll miss him not being around in one of the few shows I actually watch. I'm not one for watching an actor in something just because it's them (which may be weird of me). That said, he may have also cured me of that... would I have gone to see Hamlet in Stratford otherwise....?
d) I am convinced he's made the right decision, certainly for himself. Things and people do need to stay fresh. A part of me wonders if changing the Doctor and to Moffat simultaneously will work or not- it will be a double whammy of change that might be beyond today's audiences to deal with. That said, I don't want to believe modern TV audiences are that broken (judgemental much?), particularly not the Who audience, nor do I want to consider Moffat or whoever plays 11 as not up to it because they will be. It's just a new Doctor and a new Writer/producer team will take time to work effectively with each other, plausibly making the show stutter. Ah well, time will tell.
e)I'm also really rather worried what RTD is going to do with the regeneration. Much as I adore what RTD did in the main, he's handled the last couple of season resolutions very badly (IMHO) and I'm worried he'll be his normal arrogant, "no one ever says no to me" self, and we'll end up with something horrendously disappointing. And David can be a 'bit of a handful' I imagine, so please to be keeping him in line during the specials please.
eii)I'm hoping it works out that the Tenth Doctor realises he's done all he can do in this persona, more than a little like the Third did. EDIT: Apparently, and I just checked, this only happened in my head. WTF brain? Still. i think it would be nice for him to realise he needs to move on...
f) I'm also worried who the New Doctor ends up to be. Isn't everyone? Speculation and wank about this for the next 9-12 months I imagine. But, Doctor Who has always had the remarkable ability to withstand changes in its headline character. It's part of it's brilliance, and I am sure it will work out.
Some other thoughts and speculations:
River Song seems to be causing some contention. I am convinced the first, (or at least one of the Doctors) River knew in her timeline was the Tenth- otherwise she'd not find it so hard to believe he didn't recognise her- and she'd hardly ask if they'd done the things they'd done if she knew she'd never met him.
That she had first met 11 seems to make no sense to me within the behaviour of the characters in SitL and FotD, and I just can't believe that's the case.
(EDIT- Okay, she could have met 11 first, but I am convinced she must have known 10 before he first meets her. Substitute "first met 11" with "she didn't meet 10 before the Library" makes no sense to me.
Longer attempt to explain timey wimey is in the comments.)
Didn't I hear she was in the special or is that rumour?Maybe one of the specials will include her and an older Tenth??
There is mileage in the spin off media idea... there's a whole raft of companions that still get fic written about them who only ever existed in the spin offs. (I do have my own pet theory I'd better fic before canon eats it, really.)
Speaking of fanfic. I'm comforting myself by thinking of all the delicious fic that is likely to come out of this announcement, the specials, the speculation and the regeneration. Okay so there'll be a load of crap too, and (OMG the WANK) but I'm thinking of all those Tenth Doctor nearing his end stories that might just be beautiful. :) Hopefully Ten fanfic will continue long past the point I've stopped :)
Time waits for no man, and fundamentally, no Time Lords either.