I ordered a new Dell laptop with Windows Vista Home Premium about a month ago. I needed a Vista machine to prepare for a class I was teaching (Intro to Windows Vista), so I took the plunge. Of course, the first thing I did was reformat the hard drive, and create three partitions. The first one (C:) I used to install Windows XP, as a form of security blanket. Then I upgraded to Windows Vista, but installed it on the second partition (D:). I set aside the third partition as a redirect for My Documents, so I could access all my data from either OS.
For the first two weeks I continued to work mostly in XP, but as the deadline approached for the class, I decided to switch over to Vista. So far, I have not gone back, except to occasionally liberate something I had left in XP, like Outlook Categories.
It has been working out pretty well, and aide from having my monitor resolution change unexpectedly during hibernation, its really been ok. I might even begin to recommend it to my clients, as long as they are not using any line of business applications that are not Vista ready.
So my advice is – go ahead and take the plunge. Its been a year, and Service Pack 1 is due in a few months, which should clear up many of the little glitches that still exist in Vista. You will find the differences between XP and Vista a little quirky in the beginning, but eventually you will find all your old favorite bits. Personally, the networking piece is vastly improved and should make it pretty easy for anyone to set up or connect to a network.
For a contrasting and humorous view, you might want to read this article on "upgrading" from Vista to XP.