I thought WPF might make a nice platform to build a new application I am designing on but, after reviewing the current state of WPF (Windows Presentation Framework), I have struck it off my list because:

1. WPF can't display HTML as is and HTML to XAML converters I've seen are imperfect and too slow to use in realtime.
2. WPF can't play Flash movies nor non-Microsoft movie formats seamlessly.
3. WPF is awfully slow on low-end machines.
4. WPF is not available or problematic on non-Windows platforms.
5. WPF development tools are half-baked.
6. Windows Forms has less problems and is more complete.

Until these problems are resolved, I think WPF will be appropriate for only for building highly interactive browser-based thick clients and new bleeding-edge applications with strong control over supported media-types. My guess is that it'll take 2 years before WPF is ready as a general development platform. As a fellow engineer, I can understand engineers wanting to build a sexy looking racing yacht but a racing yacht makes a poor fishing boat.
I am now of the opinion that Microsoft has dug itself into a hole from which it now must dig, not only furiously, but smartly to get out of. Given that even the Live series of projects are lacking directions and necessary quality to attract users, I think Ray Ozzie will have to pull far more than Live Clipboard out of his hat.
Frankly, I think Microsoft could do better with less synergy between groups. With less synergy, Visual Studio would be less intertwined with SQL Server and WPF would already have support for wider variety of media formats. MSN? Why not let it compete on its own than pulling unmatching pieces together and creating an unnecessary fog of office (sorry) politic? After all, it's much easier to make 2-300 people jump together than trying to coordinate 2-30,000 people into jumping together.