Of course it doesn't use the Play Store. It's not meant as a general-purpose Android platform (and neither would any Google console). It has to have it's own specialized store. You can't very well have a console loading apps that expect a touch screen, accelerometer, etc. Even if Google let their console use the Play Store, they would have to wall it off into it's own area.
I think an accelerometer would be a logical component of a console, in the controllers though.
As for having its own "area" - as long as the app developers are careful about marking what devices the app is compatible with, there shouldn't be any problems.