Sun's studio creator has interesting collaboration-options built in: it comes with an instant messenger pane that has code-options, enabling things like copy'n paste of code (which will be sent with code-highlighting), doing code-completion in the IM window, and even sending entire files, which can subsequently be edited synchronously between both parties - very cool stuff.
It was announced that "There is no application in the gaming space today that cannot be written in Java". I find this somewhat hard to believe to say the least. The first example they gave to show the power of Java in gaming was a third person shooter that was partially written in Java (that is, none of the actual rendering used Java) not quite what I'd call overwhelming evidence. The second game they showed was 100% Java though and can be downloaded from Java.net. It looked pretty good, but only showed a 3-D view walking through the environment. There were no other characters, let alone any actual action. I don't think managed code is quite at a point yet where it can be used to create games like HalfLife 2, but I'm willing to be proven wrong...
The also showed the phantom gaming service hardware. This is a system, which supports Java (which I assume means it can do Java, but can do other stuff as well), was created by the co-creator of Microsoft's XBox. It is not a regular console, but instead can download games on demand from the network. The hardware will be free with a two-year subscription.
JDK 5 will have less dependence on command-line parameters and instead auto-tune itself for optimal performance. It will use your machine's configuration to come up with an initial config, and dynamically change settings at runtime. This is great news as tweaking stuff like NewSize, SurvivorRatio, etc. can be a major pain. This feature will NOT be turned on by default on windows though (it will be on other platforms) - use the concurrentGC option to enable it on windows.
Lucene is a Java search-engine I'll definitely have to check more into. I think there's a .NET port for this project as well (though I don't know how up-to-date it is with the master Java project) so I may even be able to use it in SharpReader.
The Groovy scripting language is, well, groovy. Using a very powerful and highly condensed syntax, you can write things in Groovy that would take ten times the number of lines in Java. Closures are especially cool. Performance is currently about 20-90% of that of Java (closer to 20% when using dynamic typing (which I guess uses reflection for every method call), closer to 90% for static typing (which takes away from the easy of use of Groovy)). This makes me somewhat sceptical of how useful this language really is right now for production systems. I'm sure they'll be able to beef up performance at some point, but until they do, I think I'd rather spend some extra time and learn Python instead if I want to use a scripting language (although I have to admit that the Java support in Groovy is pretty nice...)