Activision-Blizzard has taken no public stance either for or against SOPA/PIPA -- a good many gaming companies have declined to do so, probably to avoid backlash against their products. See GoDaddy for an objective example of shooting yourself in the face with regard to the topic -- they had a full-blown protest action aimed specifically at them once their early support of SOPA/PIPA became known and while that protest likely did negligible damage to their bottom line, it was definitely a case of 'bad publicity is not desirable publicity' that led them to back off their support.

As to what passage of SOPA/PIPA would mean to sites, fan-run-and-created sites, like this...? Both pieces of legislation are inherently hostile to the entire concept of "fair use" as far as the internet is concerned. All those nifty WoW machinima we all love so much, that get posted here every day? All it would require is one legal department *alleging* infringement and, under the provisions of these laws, it could take down not only WoW Insider but likely all of Joystiq, as well. These laws exceed the scope of even the DMCA by whole orders of magnitude.