Is John McCain a maverick because of the environment?

I have seen 2 news articles this morning that have said McCain is a maverick but they only point to the environment as an area where he disagrees. I agree that the GOP is not generally in favor of the cap and trade system. Also he has a strong history of voting against the party. However, if you look at his presidential platform, it is the same as it was 4 years ago except for the environment. I mean he could have cut and pasted from what Dubya said he would do on his website four years ago. Dubya said he would cut taxes which would fix healthcare. He said he'd lower gas prices. He said he'd be tough and end the occupation. He said he would shrink the size of government. He said no more potk barrel spending. Can anyone name a difference (other than the environment) where McCain is promising something Dubya did not promise 4 or 8 years ago?