While there is still no official confirmation from the BBC (and we stress that there's still plenty of time for this to change!), we've received enough information from various sources to safely conclude that the new series will indeed premiere on BBC1 on Saturday, March 26, 2005, likely at either 6:45 or 7:00pm (with the BBC3 "Doctor Who Confidential" series airing immediately afterwards at either 7:30 or 7:45pm.) Various sources have reported a range of rumored plans for a possible March 8 press launch, including radio and television trailers and broadcasts starting around that time; various radio interviews and photo shoots; new merchandise; a relaunch of the official Doctor Who website; and plenty of other publicity plans tying into the relaunch of the series. It also mentions that the show has been sold overseas in Canada, New Zealand and, surprisingly, Australia (for which a venue has not yet been announced), but omits the US as of this writing. As soon as we have a clearer picture of all of the various publicity plans, we'll pass the word along.
(Editor's note: Once again, I want to stress that this is not an official confirmation, but after checking with many sources, I'm now confident that this is indeed the broadcast date, barring any last minute change of plans, and that it will be announced through official channels soon. I've also been told that this date has only been finalized within the past month. More soon!)