It really is the apps - and only that.
In my case Access and Cubase, to name but 2. Not going Mac... that would signify being tied-in to an even greater extent. I don't use IM, IE, or Outlook, or Powerpoint, or Publisher... and I don't see why I am expected to pay for them. IMHO, when M$ released WinME you could see they were going off the rails.. it looked awful, was incredibly irritating, and worked very poorly.... and I guess it was around then that I decided that if M$ wanted any more of my money they'd have to come up with something I was happy to pay for at a price was willing to pay. After what we went through with Win98, WinME, Win2000, and WinXP, anybody who has bought Vista needs his head examined, quite frankly. Wait until someone has cracked it, cleaned out the bloatware, and got it to work.... would be my advice (and keep the cheapest copy you can find on the shelf, just in case, if you worry about that sort of thing)..