I don't like MSN live because it eats up to many system resources, besides I like to open different instant messaging services at once so I found that Miranda support all the messaging protocols and can be enhanced adding a large number of plugins without system hogs.
Best of all is that just duplicating a single file MSN.DLL you can open several MSN Messenger sessions with different usernames. I have one Live ID for business, other for friends and other for family, which is much better than simply grouping people and having to block many of them when you are not willing to talk with some of them.