A few people have pointed to an article that appeared this week on Forbes web site, speculating that Google might get into game publishing.
- Google's already publicly stated that they intend to do 'adsense for games'.
- Casual games sites like those mentioned, or MSN's which I worked on, while this do some "in-game ads", usually advergames or 'skinned' games, do the bulk of their advertising via interstitial ads as well as ads elsewhere around the games. For those not familiar: think TV commercials vs in-show product placements.
- Doing either of those, or even in-game ads, doesn't require acquiring a studio. Lots of examples out there today of people using technology solutions to connect ads with other parties' content.