Now that Windows Vista has the capability, we will likely add support for RAW rendering on the Windows version.
But it will be available only under Vista (which I don't use) I suppose.
Actually in my case it would be more than enough to extract the embeded JPEG and crop that according to my selection, that is why I didn't understand the problem. It is OK PM cannot render a high resolution image from the RAW but it would be nice to have all what it can do of it, instead of nothing but an error message.
Now I extract JPGs from the RAW with PM into the same folder, and have no crop set on the JPG and any on the RAW. If I choose to show RAW+JPG as a single thumbnail I see only one crop selection (that is ok), but if the RAW has one and the JPG doesn't have any than the combined view will show no crop instead of copying the other setting.
After I set the crop on the JPG (or the combined) version and Save as using Aply Crop, it successfully saves the cropped image. So PM can use the embeded image for crop, but it has to be extracted first for PM to use it. I think this could be done automatically by PM if a RAW is used like I tried and couldn't.