Google is expected to take less than 30 percent in revenue from its games, beating both Facebook and Apple. Google also has the means to operate as a "native client," hosting games on its own servers, which could equate faster loading times and fewer glitches. There hasn't been any official comment, but aspects such as In-App Payments, which would allow Google to monetize a games service, and an investment deal with Zynga, lead AllThingsD to believe the service will launch "soon," perhaps even within the month.
Google+ also has its explosive userbase to sell to developers, with over 10 million users who share and receive one billion items each day. Even if it doesn't launch this month, we're pretty sure Google won't pass up a games service in the near future.