I had a negative flinch reaction towards seeing Andrew Mason's name, given the performance of Groupon over the last few years, but then I remembered that he was the one who got that low barrier to entry, commodity business to its previously enviable position in the first place. That kind of experience of ultra-rapid ramp up and sales will surely be valuable to more than a few YC companies.
I don't agree with some of the things he did (ex: preferential exits for himself and other execs) but I wish him the best in his new role.