Not much, mainly just a few tweaks and minor bugfixes.
* Seperate SMS controls (finally) allowing for support of SMS Paddles and Light Phasers. The reason I haven't done this before is down to the UI. I don't much like the current solution, either, but it's functional for now.
* State Slots now report if they are already in use, by request.
* Allow changing state slots, and saving states (but not loading) during Netplay. I'm not sure what use this is, but it was often requested.
* Added support for a couple of Custom SRAM games that were recently discovered.
* Windows Live Messenger status updates. (thanks Gerrie!)
* Many small behind the scenes bugfixes that you probably won't notice, and I've mostly forgotten...