This release focusses on bug fixes, making the build more standard and completing the transition to the protobuf wallet format. It also includes the first preview of the native API, allowing you to access bitcoinj from C++/Objective-C++ using a straightforward, intuitive mapping from the Java API. Much easier than JNI and no JVM is required, just the libgcj support library. Examples of a native Cocoa app for OS X and a command line hello world app are included. Because it's not fully finished/documented yet, this work is available on a branch rather than in the main release.

We now have a Google+ page where we'll post announcements and developer tips/ideas: https://plus.google.com/102614914114364947458

New in this release:

Address.getParameters() and Address.getParametersFromAddress() let you figure out for what network the address is for (test, production, etc). BitcoinURI no longer requires a NetworkParameters for the same reason.
Updated to latest bouncy castle version, remove the need for the Android artifact by using the SpongyCastle build
Receives pending transactions much faster than before
Update to the testnet2 rules
Wallets now store the current chain head
wallet-tool can now create and broadcast transactions from the command line
Wallets will now be auto-migrated to protobuf format if they were previously serialized Java objects
Now uses the standard Maven directory layout
Many important bugfixes

I'd like to thank Jim Burton, Miron Cuperman, Andreas Schildbach and Gary Young for their contributions to this release.

You can get it from the download page on www.bitcoinj.org