Rumours were circulating around the middle of last season that Rooney had been seeking assurances that Utd would be investing in better players. Can't say I blame him completely. You can't expect loyalty from a scouser.

Don't be surprised if Rooney still leaves in January.
This new contract simply means Utd will be able ask a larger transfer fee and Rooney will be able to negotiate higher wages (although he'll miss out on a lot of what would have been a huge signing on fee).
I'd expect him to be sold in the summer at the latest.

The only real good to have come from all this is that we've all had another good laugh at Manchester City fans.