Went out to Vegas to attend The Java Symposium 2011. Not really fond of the location, but you have to pick your battles. It's a three day conference, but travel really knocks out at least a day.
The most interesting talks, I thought, were less about specific technology releases like JEE 6 or Java 7 or Glassfish or Apache Camel, but performance tuning techniques and war stories. In retrospect the one live demo I saw was maybe a bit of smoke and mirrors, where they swapped out an optimistic concurrency pattern using Exceptions that looks really ugly for a synchronized version and magically halved throughput. They claimed it was antagonistic performance from a 3rd party dependency, like Facebook or Twitter. The idea being that if you remove roadblocks in your code, you might discover the increased load on twitter scales even more poorly. Because apparently queues are quadratic in Web 2.0 land.
But beyond that there were interesting talks on classloaders, static analysis for performance anti-patterns, how the JVM abstraction makes compliance difficult to optimize, and the virtues of Dtrace. Many insisted the first place to look for dramatic fixes was not code, but configuration and hardware. We wound up scheduling time with one of the vendor's freemium tools next week to debug some terrible performance problems in testing environments not present in production or development. I suspect the issue is going to be insufficent hardware allocation or misconfiguration of the Oracle server; I haven't seen any version control for config of that, and it seems like a prime candidate for config and data drift. Unfortunately I don't have enough access to the test env to debug the problem. Perhaps I'll ask for that to be remedied.
The keynotes were mostly bland vendorspeak, although Oracle did claim they had no evil plan, because if they did, the past year would have been less dramatic. Because obviously they're only good at planning for evil, and fail at benevolent planning. Otherwise, lots of emphasis on The Cloud, and Java 7, and quite a bit of Open Source as a feature.