Several friends of mine have bought new machines with Vista. The computer-savvy ones comments range between "just as good as XP, but different and with some clever bits" to "nightmare - I removed it."
On a brand new machine with no "legacy" peripherals (anything more than 6 months or so old) Vista is probably not going to be a problem.
The more tricky one is Office 2007. That has got so much added feature (read: bloatware) that it's a serious learning curve to find the features you want. Some aspects of Office 2003 have disappeared - I had to remove Office 2007 from a friend's PC and install Office 2003 so that she could use the auto-text stuff she'd spent years developing for her business.
If I were buying a new PC, I'd go for Windows XP Pro and Office 2003.
I'd like a Mac as a toy, but when I finally abandon Microsoft, it'll be to go to Linux.