Andrew,
Remember that LR3 Beta 2 is still a Beta, and there is a possibility (perhaps remote) that therre might even be yet another public Beta before the final release of LR 3. Thus, my speculation (I have no insider knowledge) is that LR3 is not yet quite in the "announced" category. I think the free upgrade policy for CS5 began when the official announcement came, just about a month ago, and it is only now beginning to ship.
Can you wait off on CS5 until LR3 is really announced? Might be worth the wait.
Eric (not Eric Chan, unfortunately, or I might be able to provide more reliable information.)