Hi Kirk,
The recent Canons (and Nikons) feature 'micro adjustment'. It's kind of a hassle to adjust the camera but the results are pretty good. A variable displaying the amount of Micro Adjustment (just like in Canon's DPP) would be great to have (I know it's buried somewhere in EXIF data). It would definitely speed up adjusting.
Other variables that are buried somewhere in there and which would be really nice to have are Focusing Distance and AF-point. The first speaks for itself and the latter, in Canon software, displays the AF point used while shooting the image.
All three variables are really fine to have around when troubleshooting focusing problems (be it camera-based, lens-based or user-based). I've had my share of this (just received a brand new 1D3 from Canon after 1.5 years of trouble with my previous one) and have had to revert to Canon DPP for this purpose while I vastly prefer to use PM for everything but RAW conversion.
Cheers,
Emile