Neal Ford on ESBs:
Having proprietary glue is not necessarily a bad thing. It's one of the factors you have to consider anytime you are thinking about turning part of your infrastructure over to a externally developed piece of software. Obviously, no one is going to build their own database server -- it makes good sense to buy an existing one, and fight the nasty battle if and when it comes time to move to another one. BUT, you need to understand the distinction between standards-based and standardized so that you don't buy yourself into a real long term nightmare.
I agree, except that I believe the ESB lock-in is much worse than a DB lock-in because (most) vendors want you to put their ESB in the very center of your company-wide architecture, whereas the DB is usually hidden behind the application's outer boundary (UI or interface).
Or at least it should be. Of course, you might be using your "ESB" to integrate DB access into process flows and dare to call it SOA instead of EAI.