I couldn't find a discussion thread for this topic so I figured I'd post this here.

What do you think are the pro's and con's of having an architectural strategy that supports multiple ESB's from multiple vendors?

In your book you mention point to point integration between multiple ESBs, but don't talk about whether the ESBs come from the same vendor or different vendors. (I realize ESB isn't a product one can purchase from a vendor)

Some U.S. agencies are turfy organization, and they seem to fear that if they don't own the bus, they are somehow not in control anymore.

Of course, the software vendors say their ESB's are compatible with other ESB's.

Some of the disadvantages that come to mind if different departments choose different ESBs for their infrastructure, are obvious:
Ø Use of different development tools,
Ø Management of upgrades, patches to multiple ESBs
Ø Management of services themselves in different ESBs requiring staff trained in managing multiple tools
Ø Interoperability between ESBs (even if each ESB claims to support all the standards)
Ø High Cost - i.e. Licenses, Consulting and Operations
Ø Incremental Deployment Supports
Ø More technical issues due to the complexity of Data Sharing Architecture and ESBs interoperability

Are there other advantages/disadvantages for the federal government?

- Jeremy