We're trying something new at Y Combinator this cycle. We've recruited four YC alumni to be part time partners: Loopt founder Sam Altman, Posterous founder Garry Tan, and Justin.tv founders Emmett Shear and Justin Kan. They're going to do the same sort of work regular YC partners do advising startups, but only 1/5 of their time.They've already been working with the summer batch, and it looks like this experiment is going to succeed. The part time partners are the new founders' peers, and this gives their advice an immediacy we can't duplicate.This may sound corny, but they also make YC a happier place. We've known these guys for years (Sam, Emmett, and Justin were all in the very first YC batch in summer 2005) and have been through a lot with them. They're good eggs, and it's nice to have them around.
We now finally have search for HN, thanks to Octopart, who've been working on it for a while as a test of their new search database, ThriftDB. You'll see a searchbox at the bottom of most pages.
ThriftDB is the software they had to write to do Octopart's electronic parts searches; no existing software was up to the task. They solved the problem in as general way as possible, producing something that will work for many different types of sites that need search.
Sorry this took so long. For a while we hoped to implement our own search, but it became apparent that would take a lot of work to do right. So we were delighted when Octopart decided to get into the search as a service business. Since this was the first search app they built outside of Octopartitself, it took quite a while. This is just the first versionso it may not yet do everything users want, but it seems pretty good.
What should we measure, though? The easiest thing to measure is how many of the startups we fund raise more money after YC. By that test we're doing fairly well. Even before Ron Conway and Yuri Milner ensured the number would be 100% by offering $150k to every startup we funded, we'd got it up to about 94%.
There were 36 startups in the summer 2010 cycle, the last one before Ron and Yuri started funding everyone. Of those, 33 raised more money after YC, 1 didn't bother because they were already so profitable, and 2 were not able to raise money. So 34/36 or 94.4% either raised money or didn't need to. That number is about as high as I'd want it to be. If it were 100%, I'd worry we were being too conservative in who we funded. 
Congrats to Tutorspree, Disqus, Bump, WePay, Greplin and Hipmunk!