I have No Clue.
Apparently its the next big 'thing'.

Anybody care to shed some light on it for me?

Aloha
in quick it is a collection of what they have out now or coming out with there new technologies SQL win2k to be XP hosting technologies with some new features in IIS
and ASP technologies that will help all work together mroe cohesive
there site sheds much more light on it and this is my thought on it I am not MS shiny marketing guys though ;)
I must say there new sharepoint service looks super cool and I want to do some stuff with this for the right client adn I have one in mind ;)