This is good news (read: added Google juice) for sites that are using the Facebook commenting platform.

Previously, Googlebot was not able to read JavaScript within an iframe, which meant it did not find Facebook comments on websites. Now it has the ability to index some dynamic comments, but not all.

Here's how Facebook commenting will look in Google Search, courtesy of SearchEngineLand.

Now that Google indexes Facebook comments, websites have more incentive to install the add-on. Here's another example of a comment thread, plus the subsequent Google search for that thread.

Update: The IBTimes reported that Disqus comments are also searchable, yet when we performed a search they did not come up. I grabbed this comment from a MoveOn.org post about abortion rights. (full disclosure: I was the Associate Editor of MoveOn.org before coming to ReadWriteWeb. MoveOn uses the commenting platform Disqus.com.)

I couldn't find this comment through a Google Search.

As labnol.org reports, "some of these commenting engines are implemented in JavaScript and hence search engines may not be able to read /index the comments that visitors are writing on your web pages."