There's a lot of vendor hype about ESB solutions. ESBs are not something you just install it and wait for great things to happen, right?
What questions should someone ask before purchasing an enterprise service bus?
Help your peers ask the right questions so that they'll make the best decision.
There are two kinds of integration piece ESB & EAI. If your requirement is for basic integration(Web services) then ESB would be helpful. If you have traditional or legacy systems that communicate with legacy protocols and message formats then ESB would be a bit harder to use as you need to develop adapters for those legacy systems by your own. On the other hand EAI is an extension to ESB by vendors and it offers ready made tools and adapters which can ease your integration. But cost is involved there.