"People will be too busy browsing the Internet, playing games, watching a movie, etc. while relaxing in the vehicle. Commuting is a waste of life."
Yes, it is. I think it will be a while though before we relax in these vehicles. As a driver I am often uncomfortable as a passenger because other drivers don't drive the way I do (they make different decisions, move the car differently, have different margins of safety, etc.) Others have said though that letting the car drive itself is a huge control issue.
"Behaving with a degree of propriety has been on the wane for the past several decades."
Amusing answer ;-) I think that trust will be the biggest factor initially, and having 1 Google Car per 10,000 on the roads makes its behavior an oddity and thus a target. Make it 1 in 10, and now it starts changing road behavior in bulk.
It's a bit like these cars that can travel in convoy on highways using computer-controlled adaptive cruise control. Hooray, so long as every car involved supports that technology. It's a bit tricker when you have to mix the old and the new in the same place.