Jacky Mok, another Product Manager for Windows Live in Toronto, has posted some information on the upcoming @live addresses, which he says will be available "in the fall", along with "a rich family of products" around the same time.
According to the blog entry on livechronicles.spaces.live.com, there will be no migration of address names from current hotmail addresses, so if you have firstname.lastname@example.org, there's no guarantee you will get email@example.com. It's on a first come, first served basis. Apparently country code addresses will only be available in countries outside the US (I'm assuming a bit here, as Jacky talks only about .ca, Canadian addresses), so that a Canadian will be able to get an @live.ca address, but not an @live.com one.
Some limited migration will be available, for contacts. Other information will stay with your current accounts:
"such as: Windows Live Spaces contents (photos, blogs, etc), your emails, subscription status (hotmail plus or premium), association with other products (Favourites, OneCare, etc)."
New @hotmail.com addresses will still be available, as they are now.
Microsoft, Windows Live, @live, Hotmail, Livecom, LivedotCom, live.com