I think that you're missing the point if you think people are supposed to (or will) buy an Android phone for the sole purpose of using it as a controller...
No, I fully understand the use of an Android phone as a controller. I consider it an option that 10% of the user base will use.
I'll rephrase the question: what input device am I supposed to hand to my mother-in-law? A wireless mouse? A gyro-pointer? A mega-keyboard with a teensy little trackpad on it? And she's supposed to focus this little 32x32 cursor on the correct place on the screen?
Right now, I don't know. But it's entirely possible that in the future, your Google TV set-top or Google enabled TV comes with voice recognition and your mother in law just tells it what she wants.
Seriously, this is a clear example where Apple thinks things out a little better. We're now heading into an indefinite period of "OMG GOOGLE TV PWNS APPLE TV"...but Apple at least took the time to think out their answer before presenting it.