We do support Java 5 - so - I dont see a problem why we wouldnt support the instrumentation. I am not exactly sure about full support of WSO ESB 1.7. Assuming that you use regular communication protocols such as HTTP or JMS I dont see a problem either!
As for doc: I think there is no special doc as it is really just about getting our java agent into these systems. So - you only need to figure out how to get our -agentpath parameter into these AppServers