I've been doing linux server (webhosting) for years, so am pretty good with the server side, but when I finally changed my desktop over to red hat 9, I must admit that I was a little dissapointed. I never got any USB devices working (I've got a number of usb hard drives), and things like my digital camera didn't even have software for linux. There is some software for linux, but in general everything is written for windows.
I'm a big linux advocate, but I don't really think that it's ready for the average user (or at least my mom).