The bacteria responded with the expected genetic divergence - developing more efficent ways to metabolize glucose, for example. Then something less expected happened. One of those colonies evolved the capacity to metabolize citrate. Based on Lenksi's work looking back through the samples, the ability seems to have required three separate mutations, the first one providing no apparent advantage to the bacterium posessing it.
While this is really cool, and why I started reading this article about the whole thing, it's not what this post is about. The discussion after the article is interesting, at least partially because one of the co-authors (Lenski's student Zachary Blount) pops in about halfway through and offers to answer questions as he can. A fairly hostile questioner immediately pops in and starts peppering him with questions (most of which could have been easily answered by simply reading the initial paper, many of which could be answered by a serious look at the review papers). Being unsatisfied with the answers he got (some of which were "go read this paper" with a link), he became even more hostile. Eventually he lets loose with this whopper.
"Zachary and his paper have no credibility because he won't answer some simple, basic, objective questions about it. Zachary and his supporters have long ago passed the final point where they could redeem themselves by giving straight, consistent answers to my questions.
This paper has attracted a tremendous amount of reviews and comments. I hope that a lot of people will see this thread so that Zachary and his paper will be thoroughly discredited."
Wait. What? What kind of doofus thinks that a comment thread on a blog involving a bunch of people who are merely interested non-scientists (and certainly mostly non-biologists), has any power whatsoever to discredit a reviewed, published and ground-breaking paper?
The web sure gives some people delusions of grandeur.