I think there's a certain amount of smokescreening going on with regard to Cav's ambitions. The green jersey isn't his priority, but that doesn't necessarily mean he won't be trying to win it if he can, just that he won't go into the red to do so...
Some of quotes in this CW piece suggest a man who's quietly confident of his chances:
http://www.cyclingweekly.co.uk/news/latest/533610/tour-won-t-knock-cavendish-down.html
I love the attitude that comes across in his quotes - he could take three weeks off to do some hard training but would rather be out there racing. Yet again, he shows that he's really doing the rainbow stripes proud.
One thing we can be pretty sure of is that he'll be going for the stage win on the Champs-Elysee, assuming he hasn't pulled out by then. And I don't think him pulling out is as likely as some people seem to think.
d.