So, I used Boot Camp (2.0, the one that comes with Leopard) to install Windows XP on a small (16 GB) partition on my MacBook Pro. Reason being that Half-Life 2 won't run under VMWare Fusion...
I'll summarize the experience here, with emphasis on problems I encountered and how to get around them.
First, the good things. In contrast with older Boot Camp versions (1.0 and 1.1 for Tiger), you no longer need to burn a CD with Windows device drivers for Apple hardware. They are now included on the Leopard install DVD, so after Windows is installed, you just need to pop in the Leopard DVD into the drive, and let Windows autorun feature start up the driver installer from it. It will also install Apple Software Update in Windows, and it will presumably keep the drivers up to date (there are no updates right now, so I can't verify this. It will offer to install QuickTime and iTunes though...). Mac keyboard extras work perfectly (volume control buttons, brightness control buttons, eject button). All hardware - graphics, sound, wireless seems to be perfectly supported. The trackpad gestures also work as expected. I only maybe wish they could have made the Windows recognize Cmd+Tab instead of Alt+Tab for application switching...
Now for the first obstacle: Windows would not display image on the external display attached to my MacBook Pro no matter what I did. Others reported the problem on various message boards, with different proposed solutions. After several dead ends, I went exploring on my own. (Note: this solution works for MacBook Pro machines with an ATI chipset.) I ended up downloading ATI Catalyst Software Suite. It unpacks into "C:\ATI" folder by default. Within that is "C:\ATI\CCC" (for "Catalyst Control Center") folder, with a "setup.exe". It will tell you that it needs .Net 2.0 runtime to run. You can get it here.
So, install .Net 2.0 runtime, then the Catalyst Control Center (CCC). Don't try to install the full ATI suite, as it will not succeed, only install CCC. Launch CCC after installed. There is a tab where you can enable/disable various outputs and specify their order. Turns out the ATI chip in my MacBook Pro has 3 outputs (built-in display and two externals), of which two are enabled (built-in and one external), and one external is disabled. The trick is to disable the default enabled external output, and enable the one that was disabled! Voila, the external display lits up! (Regardless of whether you're connecting directly via DVI, or, as I do, through a DVI-to-VGA adapter -- there were reports on the net claiming only DVI displays will work. Fortunately, this is wrong.) Finally, you can use CCC to swap the order of the displays; if you want the external display to be the primary display (one carrying the start button and the tray (as I do)), you'll also do this.
That's all there is to it.
Second obstacle: with a newly created Windows partition, Spotlight had problems after booting back to Leopard. It started indexing it, and never finished. It was pegged at "3 minutes remaining" for about a day, and couldn't be used for searching during this time. This was particularly painful for me, as Spotlight in Leopard is so much improved that I use it all the time, especially as a lightning-quick application launcher. Solution was to disable Spotlight for the Windows partition. I guess you could do it using Spotlight preferences, but I did it by typing
sudo mdutil -i off /Volumes/Windows \HD
from Terminal. (Of course, your Windows partition might be named differently, i.e. "NO NAME" instead of "Windows HD".) This immediately stopped indexing, and Spotlight was usable again. This might be a problem for you if you keep some content you wish to search on your Windows partition, but since I only keep few games on it, it's not a big deal for me.
Other than these two issues, I experienced no problems and am a happy camper (pun intended).