From the site: Runs on Windows, Linux, Macintosh and OpenSolaris hosts and supports a large number of guest operating systems including but not limited to Windows (NT 4.0, 2000, XP, Server 2003, Vista), DOS/Windows 3.x, Linux (2.4 and 2.6), Solaris and OpenSolaris, and OpenBSD.
On this site, you can find sources, binaries, documentation and other resources for VirtualBox. For up-to-date press coverage about VirtualBox: blogs.sun.com/VirtualBoxBuzz
I have no trouble with Fusion, except for playing some old games, but I have 4GB RAM. I'm not sure if the 2GB you get with the new MacBook is enough.
If you want to comparison shop, Parallels and VirtualBox are also options. Others I know have been happy with both, but I haven't played much with either.
As for me, I use a 1st gen black MacBook w/Leopard, added a bigger HDD and aftermarket RAM to 2GB. I use a Logitech V470 bluetooth mouse which I carry everywhere, and I've got a couple of bluetooth apple keyboards (shorties without the num pad) - one for the office and one at home. For external monitors I've got a cheap Dell 23" widescreen in each location.
For the occasional Windows mission (usually to load updates to my N95) I was using Win XP via Parallels, but my experience with the performance of the last few releases has left me wanting and I'm currently using a trial copy of VMWare Fusion.