I've been talking to a number of customers about BizTalk 2006 R2. Its apparent there is some general misunderstandings about what is BizTalk, but I think its largely because the framework and tools extend beyond the original B2B and EAI roles. Still I think it still works best in this fashion but is evolving and adapting to new trends.
If you haven't seen the Internet Service Bus in action at http://labs.biztalk.net then its certainly something to investigate and bear in mind for future thinking.
Thanks too, to Miles Ashton for pointing me at the BizTalk R2 Database posters and keeping me up to date!