Tony Meleg said some interesting things about BizTalk Server at the Microsoft Worldwide Partner Conference in LA. You can see his whole presentation / video here.
Another blogpost I found interesting was from Richard Seroter, which is called Is BizTalk Server Going Away At Some Point? Yes. Dead? Nope.
His most important conclusion is "Is BizTalk dead? No. But, the product named BizTalk Server is likely not going to be available for sale in 5-10 years. Components that originated in BizTalk (like pipelines, BAM, etc) will be critical parts of the next generation integration stack from Microsoft."