The phone as a gaming device, rather than the touch screen gaming device, if that makes sense.

Millions are happy with the latter (the majority), but some still want the former. In other words, they want to use their phone as the gaming device because they always have it with them (powerful, big screen, et. Al) but aren't satisfied with the controls of mobile phone gaming.

"Moga has attracted support from mobile developers and publishers who want to bring console-like precision and control to their Android phone and tablet-based games. Touchscreens are fun, but they’re not great for controlling traditional games, as your fingers cover half the screen when you’re swiping."

Nexus would be touch or motion controlled gaming that feels more fun to play console-style games than traditional hardware.

We're not there yet.

Specifically: price ($50), battery-life (18 hours), and controller (basically Xbox 360).