Hi guys, I started to learn the WPF language in order to improve the quality of my softwares. I'm just a bit confused about its functionality. Maybe it's a stupid question, but could you say me if is there any compatibility problem with applications developed with WPF for windows XP ? I know that WPF is the future, and it will replace the windows form (in microsoft opinion). Many of the new features of WPF (i.e. windows 7 controls) will not be available in windows xp of course, but I heard that perhaps there could be some problems with WPF applications developed for the XP.
In your opinion what is the best develop choice? Keep learning with WPF, or keep developing with Windows Form?
Please let me know your consideration about these platform.

Many thanks in advance
Cheers
Paolo