In theory some one in the future could come up with new software to produce better results from the raw data.

To that end, I've made a point of burning CDs that have raw files and the associated directory structure that's identical to the original CF card. This means that dumb software (like Canon's ZoomBrowser) can be fooled into thinking that the CD is just another CF card (albeit read-only).

I treat raw files like negatives. They're precious and to be saved. The JPEGs I make from them are nice, but I don't stress out about keeping them safe.