Yeah, it only works on XP. But I think non XP users can download the plugins from the MSN website. There is alot of cool stuff to download for MSN.
I just downloaded a program called MSN Plus. It logs all my chats, and saves them in text format. So if someone ever told me something, and I forget what it was, I can skim through that and read up on it. Sorta like ICQ's history, but in a universal format.