I don't think Vegas would be the starting point. Nevada is in the midst of massive unemployment numbers and a massive budget crises. There are a lot of people employed in Vegas as drivers of cabs, limos and other private services. Launching driverless car services in Vegas would likely meet with massive public resistance. I could see it as another tourist attraction for the strip I suppose but I wouldn't want to test autonomous vehicles there given the crappy traffic and idiotic/distracted drivers there.
I would probably start testing in the Carson City, Reno, Sparks area. You can get a flight from the bay to Reno that takes 45 minutes. If you need to take cars back and forth to Mountain View it is only a 3-4 hour drive. The capital is Carson City so if you need access to the legislature you have it. There's also very diverse geography and lots of public roads available for testing. If you need populated areas or unpopulated areas everything is here all while being a lot closer to Google than Las Vegas is.