If Google plans to reveal and release a full-fledged console similar to PlayStation and Xbox, then the only way I see them make some noise in the industry is by creating a completely new consumer level business model for both games and gamers.
The main strategy should be, buy a full-priced game once digitally, and then play the game natively on 'Google Play Box' in high-resolution low-latency mode like on PlayStation/Xbox, but then in addition to that, you get a licence to stream the digitally purchased game free of charge on pretty much every internet connected device (phones, tablets, TVs, etc).
Allowing free streams for every game on that scale could be very costly to Google initially, but this is the only way I see them being able to shake the console market and make a big name for themselves in the gaming industry right out of the gate.