Apple has made Digital Camera Raw Compatibility Update 3.2 available.
This update extends RAW image format compatibility to Aperture 3 and iPhoto ’09 for the Canon EOS Rebel T2i / 550D and a handful of other cameras.
It also addresses RAW processing issues for the Canon EOS 30D and two other Pentax DSLRs.
For more information on supported RAW formats, see http://support.apple.com/kb/HT3825