Categories and Channels
We've just released the big recategorization work which has been occupying the whole dev team for the last few weeks. Christy has written up an explanation of it here
so I don't need to say too much. That's the big thing; there are a few more bugfixes in Pro payments and some caching changes to help with our bandwidth but check out the browse pages! I found a bunch of interesting instructables I hadn't seen before just while verifying the functionality.