I just heard about this tonight that the public beta 1 for BizTalk 2010 will occur tomorrow based on Ofer Ashkenazi’s post at http://blogs.msdn.com/biztalk_server_team_blog/archive/2010/05/20/biztalk-server-2010-beta-availability-and-virtual-launch.aspx?utm_source=twitterfeed&utm_medium=twitter.
There is an Application Infrastructure Virtual Launch event discussing various connected system technologies and BizTalk 2010 at http://www.appinfrastructure.com/ tomorrow starting at 8:30 Pacific Time. The clock on this website says it starts at 8:30 central time but this is pretty early for Redmond time so I would tune in at 10:30 central time.
I have been involved extensively in the pre-launch beta 1 so I am excited about helping the community embrace this new version of BizTalk.
Thanks,
MS Innovations Blog 
Time zone condrums I tell you! My blog is on eastern time but I work in central. The launch is on 5/20/2010.