Although I'm still a long way from being a Linux guru, I have progressed steadily in knowledge to the point where I feel comfortable using it as my primary computer operating system. In fact my newest desktop is Linux only.
My experiences with Microsoft Vista on my neighbor's new Compaq desktop have led me to conclude I don't want to have Vista on any machine of mine - ever. For a while I was thinking that maybe I'd dump Windows completely and go over to Linux cold turkey as it were. But I decided it isn't time to do that - yet.
I don't use Internet Explorer or Outlook Express. Firefox and Thunderbird Mail work great and they are basically the same in Linux or Windows XP. So the online experience is the same with both systems.
Windows XP runs fine on the older hardware I have it installed on (upgraded Dell Dimension 4100 from 2001.) XP will be supported with another Service Pack and with security updates until 2014. I don't care about eye candy and desktop glitz. In fact I have XP looking like Windows 2000 right now. There's no rush to get rid of it.
There are a few things that I still prefer to do with XP, frankly:
(1) Income tax. Quick Tax is Windows only. I could use Quicken's online service or Ufile I suppose, but I prefer having the software on my local machine.
(2) ACDSee photo management software. It's still the best, and I'd have to see if it works under WINE emulation in Linux. Not sure, but it's fine in Windows XP.
(3) Slide scanning. My old Minolta Scan Dual II can be made to work in Linux but it's designed for XP. Its software will never, ever run in Vista though.
(4) Roboform. The best password manager in the world. I'd really miss it if I went to Linux only.
In conclusion, I'd say that God willing I'm going to explore every opportunity to do things the Linux way over the next six-odd years. When XP finally is no longer supported, or I can't keep it running on my old Dell, then it'll be Linux time. Any new machine will never run a Microsoft O/S. Trust me.