Seems a bit early to me, but I just saw this:
"BBC News has announced that the actor who will play with Eleventh Doctor, succeeding current Doctor David Tennant, will be announced tomorrow.
The news will come in a special edition of tie-in documentary series Doctor Who Confidential, which is being transmitted on BBC One tomorrow evening at 5.35pm. The actor was confirmed in the role over the Christmas period, and will begin filming for series five this summer, for transmission in 2010.
New executive producer Piers Wenger is quoted as saying: "We believe the actor is going to bring something very special to the role and will make it absolutely their own. I just can't wait to tell everyone who it is - it has been a nail-biting Christmas trying to keep this under wraps!"
I suppose it would have come out, so they had to announce it themselves; but it does feel very early.