I have my MBP for OSX, and my desktop for Vista. I actually quite like Vista, and having taken care of it (ie: not downloading from unreliable sources or anything), it's been a champ.
I have a 20-inch monitor that is hooked up all the time to the desktop, but also has a spare cord that I could plug my MBP into, although I find that I don't often do so.
I definitely love having two computers and both OSes so easily available. Sometimes you just need Windows, and I hated having to restart for Bootcamp, and Parallels ran too choppy for my liking.
I'm glad you all are enjoying Vista, but I hate it. I use it at work, and I think most of the UI is atrocious. I'm not saying XP was good, and in some areas Vista looks OK -- the glass look isn't bad -- but the rest is horrible. The Explorer window layout is awful, the strange colors in various places, the fact that they took away the damn icons on the right part of the start menu and now all I have is a text list of 12 locations I use quite frequently -- without icons, it slows you down. Then there's the "security", via the name "UAC"...damn that cursed system!!! Try this: go to Program Files, right click to create a new folder and name it something. Count how many UAC clicks that takes: 4. FOUR! Holy CRAP! And don't tell me it can be disabled, I KNOW it can be disabled, that's not the point. That, and it crashed on me after only three days. And the network drive management sucks (but so does OS X's). And it won't let you have multiple monitors unless you're using the same brand video card (lame -- I used to have four monitors at work. Now I have two until we find a compatible ATi PCI card).
I too run Windows and OS X full-time like the OP...but I use XP. All I need are a few Windows programs (Outlook, Visio, Visual Studio), and there's no benefit to having all of Vista's overhead and annoying crap just to run a few programs. I actually have a copy of Vista that I got for free, but I just have no desire to use it.
I do this when I run Parallels for viewing Windows-only video or working on ****** Windows-only web interfaces.
Works beautifully - gives a nice illusion that I have two separate computers.
Though I guess I wouldn't want a Windows computer anyway, so....