Interestingly enough, just after I wrote about how Greplin had some social search benefits that Google is lacking, Google announced that it has updated its own social search. Google social search results will now appear mixed throughout the organic results, as opposed to just at the bottom, as they have done in the past.
It's a good move, as I believe that often times, results from people you know is a big factor in relevancy. It's easy to ignore such results when they're at the bottom of the page. Still, missing from the mix is Facebook, however. Since most of your social activity and your real friend connections are most likely occurring on Facebook, this is a pretty big hole in the social search experience. According to recent estimates, Facebook has about 600 million users.
Google says you'll see updates from Blogger, Twitter, Flickr, and "publicly available sites". LinkedIn is also shown in a screenshot.
Unfortunately, I can't see the available accounts in the settings yet. Google says they're just starting to roll the feature out, and we'll see it in the coming week.
According to Matt McGee at Search Engine Land, you won't even see public Facebook Page results. Google's Mike Cassidy told him, however, "This is just the beginning, and we're going to be doing much more to improve the comprehensiveness of Google Social Search." He also has a graphic that seems to indicate Google will include YouTube, StumbleUpon, Reddit, Quora, Delicious, and Digg as well. "
Greplin still has some advantages over Google as far as social search (Greplin results could be awesome, mixed in with Google's results). Adding other Google services to the mix would be helpful (and more Greplin-like). Why not include Google Reader, Docs, Picasa Web Albums, Gmail, etc.?
Google has added some elements to its social search though - apart from just mixing the results in. They've added notes and links people have shared on Twitter and other sites (before, they just showed results people created and linked through Google profiles). They've also given more control over how you connect accounts. In addition to simply adding an account to your Google profile, you can add an account privately, just so you can get the results in search.