Hmmm, I may have spoken a tad early.
The XSLT scripts I found only translate the very basic deployment descriptor elements. The remaining elements are usually of the vendor-specific performance optimisation type which often don't have a 1-1 equivalent, if they have one at all.
The JBoss community forums are very quiet on these fronts. Perhaps there is a conspiracy to drive me to JBoss.com's migration programme...
Grumble.