I wasn't there so if they were genuinely STRIPPERS stripping their clothes off down to thongs/breasts then we have a problem because would be completely inappropriate.
However if they were nothing more than dancing girls in sexy clothing then that is more than fine, they're just there to dance and put on a show. The word "stripper" seems to be getting tossed around rather lazily in this thread, it makes me think people know what an actual stripper is and what an actual stripper does :S
edit: Yup, digging up more info on this incident, here we go: http://www.forbes.com/sites/carolpinchefsky/2013/03/27/really-igda-party-at-gdc-brings-on-the-female-dancers/
Strippers my ass, just TWO dancers. However it seems that enough people complained about that so the IGDA won't be doing it again. I can see that it was inappropriate, this wasn't just some typical gaming convention/party. Fair enough.
The fact that it made the female co-chair of IGDA's Women In Games Group step down [http://au.businessinsider.com/igdas-after-party-with-women-dancers-2013-3] is HILARIOUS though, so that's all it takes to make a feminist run away? Talk about over-emotional