When I saw the demo of the newly announced Windows Workflow Foundation (WWF) in Wednesday's PDC05 keynote, I quickly replaced the sessions I had originally planned to attend that afternoon with three straight sessions on WWF to get a better handle on what MS has done, and I must say that I am quite impressed and excited by what I saw.
We've probably all written workflow-like stuff in just about every app we've worked on, but rarely is it ever done the same way twice. To have the fundamental mechanism provided by the platform is very exciting. It is cleverly designed to be a small, lightweight framework that you can easily host in your own process, with a business rules engine, and a VSNET hosted graphical designer tool to boot. It doesn't try to be all things to all people, but rather provides just the fundamentals, leaving extension points for you to write custom Activites to do virtually anything you require. Bravo to the MS team, I can't wait to get the bits installed somewhere to start playing with this more.
Unfortunately, as is true with every PDC I've attended, I get all excited about some technology we can't start using for "real" yet. I think I heard estimates that WinFX won't release until some time in the second half of 2006.