This one seems to be a bit more of a new way of working than just an upgrade.
Upgrade suggests doing the same things in a better way. A new way would suggest we will change how we work.
XP has done some of that already (grouping on taskbar, no BSODs, system restore etc) Longhorn could have a much bigger impact on the way we intereact with a PC.
He's just buidling some hype anyway :))