If you want a quick and easy way to find out what exactly is new in Java 7, take a look at this short series of videos.
There isn't a great deal to add to these videos except that they are difficult to find as a set. They are all courtesy of Oracle via the offical Java You Tube channel:
Part One - Project Coin
Part Two - NIO
Part Three - Concurrency
Part Four - GUI (It claims to be part three)
It isn't clear if they will be a fifth part, but if there is it will be added to this list.