I know this is an old question but I just wrote a tool to help make long thread dumps more readable.
Java Thread Dump Analysis Tool
This tool groups threads together which have the same stack trace and allows you to only show threads which are in particular states (e.g. RUNNABLE or BLOCKED).
This makes it a bit quicker to find the interesting threads amongst the tens or hundreds of JBoss threads which spend most of their time waiting for work at the same place in the code and therefore all have the same stack trace.
