Update: Full transcript of video interview is here.

It turns out those rumors last week were accurate. Microblogging site Twitter has acquired the Summize search engine, Twitter co-founder Evan Williams confirmed to me. The size of the transaction is not being disclosed, although the transaction price was paid “mostly in stock.”

Twitter has also hired 5 of the 6 Summize employees. Founder and CEO Jay Verdy will move on to a new project.

The five Summize employees joining Twitter are all engineers, adding to the twelve engineers that currently work at Twitter. Summize CTO Greg Pass will become Twitter’s top tech guy as Director of Engineering and Ops.

The deal has been discussed for some time, Twitter co-founder Evan Williams told me earlier. The companies had a term sheet in place when Twitter partnered with Summize in June to help them keep the Twitter platform stable during the Apple iPhone 3G Steve Jobs keynote. The deal was closed in the last week.

John Borthwick, a partner at Summize investor Betaworks, was also an investor in Pyra Labs (Blogger.com), which Evan Williams co-founded in 1999. In other words, the companies were already kissing cousins.

I spoke with Williams over the weekend at Foo Camp about the transaction and other Twitter issues. The video is below. We’ll post a full transcript later today.

Twitter may buy Virginia-based Summize, a Twitter search engine, says Jason Calacanis. A source close to Twitter says that the two companies have been in discussions around a merger over the last couple of weeks, but won’t comment on whether an actual sale has occurred, or the terms.

The deal certainly makes sense. Unlike rival Friendfeed, Twitter still lacks a search feature. And Twitter has relied on Summize in the recent past to help reduce load on the Twitter API. Summize is also one of (or the only) Twitter partner that has access to their XMPP stream.

Summize employees have recently been spotted at Twitter HQ as well, although that could be explained by the close working relationship.

Summize has raised just $750,000 in an angel round of financing. Twitter has raised over $20 million.

For those of you who just can’t wait to hear the latest Apple news this morning as it breaks (our live on the scene coverage begins at 8 am PST): Twitter is partnering with Summize to show all twitters that contain the words “wwdc,” “apple,” “iphone” or “steve jobs.”

Twitter is promoting this heavily on every Twitter page with “Apple fan? Our pals at Summize are tracking the WWDC.” I didn’t notice it myself (I use Twhirl and rarely visit the Twitter site), but others have.

It’s no surprise that Twitter is pushing this – they are actively trying to find ways to reduce the database load on their frail infrastructure during the event, and pushing users to a third party service will help. If Twitter goes down, though, there’s nothing Summize will be able to do to help.

Watch the news here.

I’ll say one thing for Twitter, They have community dedicated to keeing the service alive. Pushing page views and the constant refreshes to a third party is real service. Golf clap for Summize.

When Michael’s internet went down last month, he vented his frustration on Twitter. And lo and behold, Comcast actually saw his tweet, reached out to him, and proactively worked to solve his problem.

Comcast is unusual in its embrace of the Twittersphere, however, since it actually has someone dedicated to putting out fires there before they tarnish its brand too much. Not all companies have that level of savviness so Get Satisfaction, a network of customer support forums, has started to monitor Twitter for them.

Using Summize’s public APIs, Get Satisfaction now records all of the messages on Twitter that mention brands of supported companies. Did you just complain about your experience on eBay? Go here to see your message seeded as the start of a possible discussion thread.

The system’s meant to help companies respond to customer concerns on Twitter, since all followup messages on Get Satisfaction are tweeted back to the original tweeter. Its also meant to create a public dialog around these messages so that other customers can learn from their peers’ experiences. And since much Get Satisfaction is about customers helping customers, it provides a forum for them to do so in a more purposeful way.

Get Satisfaction is working on additional functionality that records all the tweets centered around an original tweet. So, in Michael’s Comcast case, the company and its other customers could have better tracked the public’s response to his ordeal.

Sometimes reading online product reviews can be a real time sink. There are so many opinions out there—from CNet to Amazon to blogs. It can take a long time and a lot of sifting to figure out what people really think. But now there is another way. If you want a snap shot of popular sentiment about a book, movie, CD, or gadget, type its name into Summize.

Started by two AOL expats a year ago, and launched in a public beta last month, Summize does sentiment analysis across dozens of review sites and more than half-a-million blogs—what CEO Ajaipal Virdy calls the “reviewosphere.” These include review-heavy sites with ratings, reviews, and other structutred data like Amazon, CNet, IMDB, and Epinions, as well as active blogs filled with unstructured, unfiltered opinion. In that sense, it is a cross between CNet’s Metacritic and Blogcritics. Explains Virdy:

We algorithmically analyze the review text to learn the polarizing words that correlate with user-assigned star ratings. We use our knowledge of polarizing words to extract the opinions from unstructured blog posts, and algorithmically assign them ratings.

Summize harvests all of this opinion and boils it down to a single heat map that it calls a “snip.” This is a horizontal bar with colors ranging from red (wretched) to yellow (so-so) to green (great). It attempts to capture the collective sentiment about any given product at a glance. For instance, out of 21,021 opinions about the band Radiohead, 67 percent are “great,”, and only 10 percent are “bad” or “wretched.” The band’s most reviewed album is Kid A, the most liked is OK Computer, and the most buzzed about is their recent online pay-what-you-want freebie In Rainbows. There are links and excerpts from recent blog posts about Radiohead. And, in a nice twist on Amazon-like collaborative filtering, every product has a list of related products. In this case, “bloggers who discuss Radiohead also discuss” Band of Horse, The Pixies, and Idelwild.

The site feels a little thin for some products, especially newer ones. But the approach is promising. Summize plans on adding other categories such as travel and restaurants in the future.