Microsoft has the most comprehensive integration platform and vision bar none!
From the theserverside.net, "A new report from the Burton group says that Microsoft has the most cohesive "superplatform" offering. The Burton Group defines the superplatform as a tightly integrated suite of products that provides a platform for enterprise computing. The analyst firm also places IBM, BEA Systems, Oracle and SAP AG in the superplatform vendor category."
Read the complete story here.
In addition check out the ESB whitepaper published by the connected systems group. You can read a copy of the paper from Scott Woodgate's blog here.