Microsoft has released a statement on its official position on the Enterprise Service Bus (ESB) concept. You can find Microsoft's statement through this blog post of Scott Woodgate (the Lead Product Manager for BizTalk).
As expected Microsoft positions BizTalk and Windows Communication Foundation (aka Indigo) as its offerings in the ESB space, but will not market this combination as an ESB.
Thanks Edward for pointing me to this document.
I am not quite sure how the BizTalk/Indigo combo will enable location transparency for services. Nor how it will enable you to distribute the service bus transparently over multiple machines.
Will BizTalk v-next-next go beyond the hub-and-spoke and the single MessageBox model? Say you deploy multiple BizTalk machines to form a distributed bus (meaning not deploying multiple BizTalk servers to increase availability, but to distribute geographically). Can you easily design a business process that spans multiple BizTalk servers? Can you monitor multiple machines as a whole (for both Business Activity Monitoring and infrastructural monitoring)? Can you configure the bus as a whole?
Please leave a comment if you have an opinion on these matters. Maybe you think having such centralized control over a single bus is not necessary. Or you think that services should interact point-to-point as much as possible instead of through a broker and use a simple directory service to look up the addresses of other services.