Lol, Microsoft asked most of us to upgrade months ago. It really sucks, and it's crappy. Takes long to load and has such limited features, or atleast features I do not need. I like Windows Live Mail Desktop though, yet my ID doesnt work with it atm.
personally, I do not like it very much because 1.) it can't run in firefox, MUST be IE 2.) it takes like a long time to load opposed to gmail or yahoo or whatever 3.) they block a lot of stuff that doesn't get blocked in other services like gmail for example. almost everything that comes in comes as "unknown sender" and there's an intruding yellow warning bar. grr.