Some consistency from IBM and Microsoft on ESB as a way of achieving SOA
Bobby Wolf basically points out, which many realists that have worked with ESBs, MOM, Services (SOAP) have already figured out - that an ESB is just a tool and not the answer to having a Mature SOA. Just as Web Services (SOAP over HTTP) has been viewed incorrectly as SOA on it's own merits, ESB's are also just part of the picture.
Before you start putting all these frameworks, tools, components in place, take a step back and understand the business domain first. As Mr. Wolf points out, and what I try to instill in any conversation first regarding SOA, first, look at the Business Domain - then, align the technologies (existing, legacy, new, WS, ESB, CORBA even) to bring you to a greater level of SOA maturity.
An ESB is just a tool, nothing more. A good tool when done right. And that answer is not just 42 (huh?)
ESB-oriented architecture: The wrong approach to adopting SOA
Such an ESB-oriented architecture is easy to envision, but its success is difficult to measure. What clients requesting such projects do not understand is this: An ESB-oriented architecture does not produce business value. A project based on ESB-oriented architecture needs to be made into one based on SOA-oriented architecture to help ensure that it successfully delivers business value
ESB-oriented architecture: The wrong approach to adopting SOA