I knowthis is late in the ballgame, but I'm jumping in on my serpentine belt ('07, 2.4, auto, LT Panel wagon. All the posts from '11 are life and money savers. Thanks guys and gals.

Hope the info above helps ya
There is that mid year change.
If you make or borrow a tool and get the right size belt
It's a 5 minute job.
Good luck
If you can still read the gm # on the belt
that will help them cross it over.

The tool is the problem. The "standard tool" will not work at least on a 2.2L. What I did was go to Harbor Freight and bought a set of adapter things that have a hex on one end and a square socket adapter on the other, I think they were called "Hex Caps". The 3/8 square has a 9/16 hex, ground the square side down into the ball bearing (about 1/4 inch). So now the adapter can be inserted. I then applied a bit of Duck Tape to the 9/16 hex so that my open end wrench would stay on it. Then ran a piece of wire thru the box end to pull the wrench up and tie to the hood support. After that you just need to get bloody knuckles, 15 minute job after fabricating the tool. I left out the parts about taking the plastic panels off.