Apparently, ESPN3 is not available with Google TV
I wasn't sure until Friday when I was at Best Buy and someone was returning GoogleTV and getting Apple TV. In fact, I was one of 3 people buying Apple TV specifically to see the MSU regional games.
Like those who have posted before, you have to know if your InterNet provider is compatible with it. And the live streaming does eat away at your data allowance. I have DISH and my package includes 15 gig of data per month and if I run out I have to pay $10 for each additional gig until it resets back to 15G at the end of the cycle.
(there is off peak data of 15g for 2am to 6am only...which I never use.)