Update (11:45 AM) – The Australian website has revealed that the games will be released in Australia and New Zealand on March 10th.
The March 4th date on the TPCi holiday card has been identified: it is the release date for Black and White in Europe! That means they will get the games two days before us (Friday compared to Sunday); this is the first time Europe will be getting a core series Pokemon game before America.
The only remaining question now is when the Best Wishes dub will air. The Diamond and Pearl animé aired on Cartoon Network the Friday before its Sunday release, so there is still a possibility the same could happen this time.