Yeah, you need a fairly modern PC. On my P4-2.4GHz, it takes something like 10sec/picture for the raw transfer, which is about the same as the USB transfer time. Again, it's fairly easy to overlap this with doing "real" work (comparable to ripping CDs in terms of how often you need to babysit the operation), and it's worth it for the occasional picture that you want to truly "perfect".

Incidentally, some new cameras, like the aforementioned Sony, will record both a JPEG and a RAW file of the same shot. This increases your common-case throughput (assuming transfer time and disk space aren't issues for you), while still giving you the option to do later touch-up.