I needed to logout of my wifi network after rebooting and then log back in to get a proper ip address. I suppose a second reboot would've worked just as well.

Also for anyone running Windows XP on their MacBook, I needed to reload the xom.efi. Before doing that, my Mac would automatically reboot in OS X without the option to boot into Windows.

BTW: Windows XP runs friggin' awesome on the MacBook. There's no graphic hardware acceleration, but other than that, it's the fastest Windows PC I've ever had.