On blog posts I read that BizTalk Server 2009 is available on MSDN and through Volume License Key. This means as BizTalkers we can start working with official released product. I have started with yet again a sandbox installation with MSDN BizTalk Server 2009 Developer Edition. And try a couple thing out like Brian Loesgen post Walkthrough: Composite Operations with the new WCF-based SQL Adapter.
Technorati:BizTalk Server 2009