Earlier this week David Dagastine was quick off the mark reporting HotSpot as:
"the fastest, most reliable, and most widely deployed, open source Java Runtime in the world"running on an Intel Nehalem. Unfortunately a bit too quick, since he didn't wait for the results to come in from IBM's J9 VM which posted a faster result as reported by Derek (who is, allegedy 8-10% better looking too)!
The HotSpot results were partially attributed to improvements in the class library, which David (when challenged by Mark Wielaard) tells us "need additional work to integrate into OpenJDK, but that work is in progress now" -- I assume that they are in the same queue as the TreeMap performance changes that are apparently in the process of being contributed back to Apache Harmony.
So today "Sun Java powered by the HotSpot Server VM" is not the fastest and not open source. Looks like some catching-up to do again.