Well, I tried G9 profiles for A650 that way. Both cameras have the same sensor, so G9 profile should be good. And - Camera Standard beta 2, which should produce the same colors as jpeg from camera, was quite near (after adjusting exposure, brightness, contrast and some WB correction), although my extensive test image shown that it was far from identical.
On the other side, Adobe standard beta 2 for G9, used with A650 raw, was expected to give me the same colors as 400D raw with Adobe standard beta 2 for 400D, but that wasn't the case. Colors were quite off - red tends towards magenta, green foliage toward yellow and sky color towards cyan + some differences in white balance
Adobe standard profile for G6 also wasn't very good for A620, although both also have the same sensor. There was a big difference in WB. After correcting WB, colors look similar to 400D used as reference, but didn't have time to make more tests.
Another thing, Canon in-camera rendering and rendering of Camera Standard profiles provided by Adobe for Canon is quite different from rendering of Adobe Standard profiles. Foliage has almost 10 deg higher hue and looks too cold for my taste, and sky also has about 5 deg higher hue and looks too violet for my taste, orange is too dark etc ...
You can use lookup table from profile to get Nikon colors from Canon (or every other) raw files (using Camera profiles), but since sensors are different, you can't use the profile as-is (at least not with great success), because color matrices in the profiles are unique for every camera, and matrices for APS sensors are considerably different than matrices for sensors in compact cameras and will generally give you less saturated images + differences in white balance and hue
Unlike Camera profiles, all Adobe Standard beta 2 profiles have the same HSV lookup table, just color matrices are different. There are 4 color matrices in a profile now. Color matrices for each camera are the same in all profiles for that camera (for example Adobe Standard beta 2 for G9, Camera Standard beta 2 for G9, Camera Vivid beta 2 for G9 ...)
