While like tgrech I'm split on whether Google will abandon this like they've done with a lot of projects in the past. I can see how it could take off since it doesn't require a console. Just a controller which can be used with a lot of different streaming devices.
A lot of people who move around a lot will like this since they don't need to lug a console with them, just a controller which is a lot smaller, lighter, and cheaper. Then beyond that, they just need access to a device that can stream everything, which these days isn't hard to come by.
The only thing that I'm concerned with is the longevity of the platform itself, since it's all digital we don't 'own' the games so when the platform shuts down, that's it.