Looks like Windows Live Mail Beta has seen an update, this beta program is open to those that request to partake from what I see and is Microsoft’s next generation replacement for Hotmail. It looks like it will be quite well Ajax-ified and some interesting features for classifying mail by senders (known/unknown/unsafe) is interesting.
I have a hotmail account from years back. I never got much there but junk. Then they added junk filtering and now all I get are special offers from Hotmail ( “but our junk is GOOD”). I’ve never been as interested in Hotmail as in the yahoo mail or gmail. Maybe this will offer features that make it a “killer app” for “web 2.0”