I have 2 HD's in my PC, one for serious stuff, other for er.. other stuff :-D, wich is the one I use the very few times I connect to the internet from home (dial-up). When I do so I allways disable the HD with serious stuff from the BIOS just to be secure.
Now check this out. Last time I coonected just to check mail and within 3 or 4 minutes the "MatrixHasYou" virus got into my machine! It's Win2K with SP4. Ok I got no AntiVirus but a friend of mine has (can't remember wich one) and he got infected too. Maybe his antivirus wasn't updated for a moth- week whatever. The thing is PC's have gotten so vulnerable that "normal" people will never be able to use/maintain one without getting infected, or spend $$ every month!!
Time to get my Amiga online I say :-D Been also thinking about installing Debian on the X86 machine for a long time but I really don't feel like taking the time to learn/get used to yet another OS.
My point is, if FireFox has become popular because it's more secure (ok and with a few cool features like tabs), or because IE has become extremely vulnerable, then maybe it's not that difficult to convince users to at least try different platforms, specially since most of these virus are actually written to steal personal information on credit cards, paypal, ebay, mail whatever account data...
