Currently Being ModeratedJan 4, 2013 7:13 AM (in response to canardxpan)
I came across this really old question and noticed it still hasn't been answered. Unfortunately, there is no option in Aperture to correct lens distortion, let alone use it from XMP data. You have two options, either use a plugin such as PTLens, or use Photoshop as your external editor. Both will result in a TIFF being generated from your file.