Read the announcement here. It's actually the pre-release version, nevertheless it's quite stable.
What makes this version interesting? It's got reversible debugging, which means that it's the first time you can actually make your code go back in time to find out what it did before it crashed.
I've tried the new commands, but I'm haven't been successful in stepping backwards still - well more experimenting ahead!
Update: The tutorial is available at
http://www.sourceware.org/gdb/wiki/ProcessRecord/Tutorial. (Thanks to Michael!)