InfoWorld: Doing the impossible with Longhorn: By Jon Udell "It’s funny how circumstances can change your perception of what’s possible. A few months ago, key Microsoft architects were telling me that it would be impossible to decouple the Avalon presentation subsystem from the Longhorn OS. Now they’re huddling in conference rooms trying to figure out how to do just that. It makes me wonder what else might turn out to be possible after all."
More excellent insights and context-setting from Jon Udell.
My $.02 on the Longhorn changes:
1. I'm surprised Microsoft didn't announce some kind of partial Avalon-on-XP sooner. Few developers were likely to exploit Avalon if it remained Longhorn-only, given the protracted Longhorn deployment cycle (even for intranet app contexts).
2. Most of the press/punditry assumed, until the recent announcement, that Longhorn was going to arrive in 2007 at the earliest. Now it's clear Microsoft is determined to ship Longhorn in 2006, albeit with WinFS planned to be in beta when Longhorn launches. Somehow the conventional wisdom now seems to assume that WinFS has gone the Cairo route, and will never ship. To recap: Microsoft plans to ship Longhorn in 2006, and WinFS is expected to be in beta then -- i.e., for most people, this isn't a huge recalc, in the grand scheme of things.
3. I expect to see some sort of "WinFS lite" on XP, for the same reasons it's pragmatic to deliver a subset of Avalon on XP. Architecturally, WinFS is an abstraction and service layer atop NTFS and SQL Server; Microsoft may not be able to deliver 100% Longhorn-level compatibility on XP, just as it can't with Avalon or Indigo, but it can (and will, I believe) go far beyond the 80-20 level in delivering parts of WinFS on XP.