Actually, David, it’s been more than three years. But we won’t hold that against you.

BBC News: David Tennant on Doctor Who exit (includes 10-minute interview explaining his reasons for leaving, his memories working on DW, and his choice to be his replacement)

(Just so we’re all on the same page: David Tennant’s final episode as the 10th Doctor will take place in late 2009. He will go into production of the four gap-year specials in January.)

When I first saw this, I was quite surprised. I was listening to a podcast recently, and it was mentioned that on one of the S4 commentaries (episode 13 I believe), Tennant referred to Steven Moffat as his “boss”, which kinda implies that Tennant’s sticking around for season 5 (to air in 2010, the first with Moffat as executive producer). So, with that piece of information as my reference, you can imagine my shock when I read the BBC pieces on his departure.

David Tennant effortlessly took the baton from Christopher Eccleston in 2005 with great confidence, but after a first season that saw him getting his feet wet, he found his stride with “Runaway Bride” and subsequent seasons. His Doctor’s manic energy is infectious, but he is also still affected by the catastrophic Time War, and Tennant manages to find that balance.

I see some precedents for his departure: his “three years” were clearly based on Patrick Troughton’s and Peter Davison’s pre-determined three-year limits. I don’t know if Davison told Tennant to max out at three years, but given that they’ve worked together in “Time Crash”, and Tennant is dating Davison’s daughter, it is a possibility. The interview also mentions using Russell T Davies’ and Julie Gardner’s departures as a “stepping off point”. The departures of Troughton and Jon Pertwee coincided with similar announcements by the main players in the production (Barry Letts and Terrance Dicks in Pertwee’s case).

So this means that Steven Moffat pretty much has a clean slate to work with. Hopefully he provides a majority of the input regarding Tennant’s successor. And so let the speculation begin…