BizTalk Server an ESB?

During my Biztalk Server training I have been asked several times whether Biztalk is an ESB or not.
Especially in the Java technology domain ESB is becoming more and more popular. For example recently BEA released Aqualogic Service Bus.
I always said that Biztalk has all the features that you would expect from an ESB like routing and . . . → Read More: BizTalk Server an ESB?