I put my thoughts with code examples http://www.infoq.com/articles/java7-nio2
1. new file io giving control over modern file systems especially POSIX alike.
2. Auto resources freeing
3. Forks for easier parallel programming
4. Switch with "String" cases (absolutely love it)
5. <> for reducing typing efforts
6. Just forgot variable arguments improvements giving me possibility to create generic arrays.
I am spoiled by Java 7 and can't wait using Java 8 with default methods, enclousers and other bells and whistles. What about you?