I've had XP as a vm in VirtualBox for seven years now, almost to the day. First on RH/Fedora and Debian, then Ubuntu, then, when I switched to Mac completely, on OSX. The single purpose of having XP, for me, is to be able to access and work with tons of CorelDRAW X3 files, that I'm just too lazy to convert to inDesign or Scribus, or PageMaker before that - if it ain't broke, and all that ...
Apart from the initial setup and service patch install, this virtual machine has never been allowed online, and now never will be. Thanks to some skin app I forgotten the name of, it looks like OSX and when I need to use it, about once every couple of months, I don't feel like I'm violating my own "no Microsoft products" policy