The new code kicks ass in so many ways that I won't try to explain it concisely. I'm not too good at that, anyway. Let's just say the new code is totally sweet.
The new code supports clusters, but we're not using them yet. Tomorrow or so we will be. In the meantime, there's about a billion other things that should make the site faster.
But, there are probably bugs. 6 good bugs were found during the beta test and none have been reported since. But we'll be watching things closely.
More news coming over the next few days as we get the clusters online. We have a ton of new hardware arriving next week. Then we get to start moving users to clusters and things get even faster.