Here's to hoping there's a public beta released at Mix.
I think that's pretty much 100% guaranteed (although they might call it an "alpha" or "CTP" or some such nonsense).
My money's on Silverlight 2.0 beta and go live license also being announced.
Any other guesses? Place your bets here.
The irony is that the non-attendees usually get this stuff first anyway. It's all prepared and launched around the time the keynote gets delivered but of course attendees are stuck in sessions with appaling conference wireless access while the rest of the world accesses whatever's been launched via Broadband. Such is the power of the internet.