Java Performance MythBusters motivated me to propose round 2. I expect that the time until next years EclipseCon will bring some new insights and refined numbers, too.
After all, Java8 is currently under heavy development and so it's quite likely that the measured times and numbers will change dramatically. And of course it will be interesting to take a look at the performance characteristics of other platforms, e.g. Linux and Windows.
Which topics would you be interested in? Run-time cost of reflective access? Arrays vs collections? Auto-boxing? There are still plenty of myths out there and I will again pick some of them to go for the next round. Let's put them on the test-bet!