That'd be cool. The article is questioning whether there would be value in upgrading to Longhorn if all of its pillars are available for Windows XP. I speculate that Microsoft will be first offering consumers an intensive to upgrade by offering a new user experience (Aero, new driver-support, multimedia device integration/support, OS componentisation, etc.). The transition will be tested through OEM-supported distributions before Microsoft releases a follow-on version plus the server version which will aim to attract the large customers and businesses. I think such an approach makes sense.
Really really looking forward to Longhorn and its technologies. Avalon and Indigo CTPs should be available this month. I am going to be producing SSDL-related tooling for Indigo and further developing my 3D star browser using Avalon. Stay tuned.