The issue that Matt pointed out wasn't just one of GPL, but the very fact that Pearson tried patenting common WP features (which should not be patentable).

But it can be done by unethical people using lose wordings to describe a prior art. And in the long run, Pearson (and whoever who follows what he is doing), and then use these patents to punish regular Wordpress users and commercial Wordpress businesses. Which is the main issue here.

If you are sued by Pearson's patent (that is assuming he doesn't try and get more), would you be able to defend yourself in court?

That's why I fully agree to Matt's decision to buy over thesis.com :) Let's put people like Pearson out of business. And if needed, sue him for profiteering and abusing the USPTO with vague patent applications.