You may be able to open them if you first convert them to DNG using the Adobe DNG Converter (free).
I hope you're annoyed with Canon.
Is there ANYWAY to work around using CS5 and still open my CR2 files!?!?!?!?
"A lot of people ask, “Why do I have to buy a new version of Photoshop or Lightroom just to get the latest camera support?”
The answer: You don’t have to. Adobe provides backwards compatibility for the latest cameras forFREE in Photoshop CS2, CS3, CS4 and CS5, as well as Lightroom 1, 2, 3 & 4, through the Adobe DNG Converter."