The interesting thing about this is it is, to my knowledge, the first time that destruction of infringing books was demanded.
To date, even with the most egregious violations (not including the OGL, using OGC "designations" that leave it to the reader to deduce what is or is not open content, using other parties' content without updating the Section 15 of the OGL, using non-Open content from WotC, etc.), publishers were essentially slapped on the wrist and told to put a note on their website and fix it on the reprint. (Note that VERY few d20 books are ever reprinted, so this is not much of a penalty.) In the very competitive d20 space, then, it has become a liability to spend any time at all on license compliance -- a cost (of staff time) without any clear benefit (since the "penalty," if anyone brought non-compliance to your attention, was less costly than doing it right in the first place).
This event suddenly means that publishers will have to re-evaluate the cost/benefit equation with respect to license compliance. (They may still calculate that the odds of getting a nastygram before substantially all of a book's print run is gone out into channels and paid for, making the question of destroying remaining inventory moot, mean it's still not worth worrying much about the licenses.)
I think Fast Forward does deserve credit for being open about this, explaining what was done wrong and what were the consequences. One of the problems with license compliance issues to date has also been that they have happened in the back rooms, for the most part. The lack of transparency has led to misunderstandings: some people have had the mistaken impression that doing something was OK because someone who did it was not punished (as far as anyone knew). Other people believe persistent rumors that nastygrams were sent in cases where they were not. FFE's openness is a service to the whole OGL publisher community.