Jeff Atwood discusses it extensively in his blog posts entitled Programming Is Hard Let's Go Shopping and Parsing HTML The Cthulhu Way.
"So, yes, generally speaking, it is a bad idea to use regular expressions when parsing HTML. We should be teaching neophyte developers that, absolutely. Even though it's an apparently neverending job. But we should also be teaching them the very real difference between parsing HTML and the simple expedience of processing a few strings. And how to tell which is the right approach for the task at hand."
Find more details in the posts mentioned above.
