Dang, I didn't know about this... thanks! As soon as I get back to my Mac I will see if I'm affected by this issue, since I use my .Mac email as my MSN ID.
Pretty sure you'll be affected.
The transition has been fine, all my contacts are on my new ID, and it's not like I had to import a list from my old account, it's still the same thing, they don't have to accept my add again, so that saves some hassle.