A former Softie friend of mine IM'ed me about this job. Sure, you need C++ skills, but there's more to it than that. They need a variety of skills because you'll get to do a variety of work... off the top of his head he listed:
- multiplayer game infrastructure
- chat and presence application
- drm / installer
- IE toolbar
- flash applets
- a bunch of other stuff
There's a Craiglist ad, which includes application instructions. This is in Seattle, by the way.