This week's giveaway is in the EJB and other Java EE Technologies forum. We're giving away four copies of EJB 3 in Action and have Debu Panda, Reza Rahman, Ryan Cuprak, and Michael Remijan on-line! See this thread for details.
I believe Java is introducing at least the safe navigation operator in version 7, and of course there has been a debate raging within the Java community for a while over closures. Of course Groovy has the benefit of not having to support such an enormous user base, so they have probably had more freedom from the beginning. Java will take a while, and may indeed never catch up with some of these features.
The syntax for collections, such as Lists, Maps and ranges is also much less verbose in Groovy than Java.
Of course, I cover the basics of these features in Chapter 4 of my book!