For the past one week I am at Bangalore attending a training for Windows Vista.
We used to struggle to get a nice, jazzy UI for apps, which is far easy in WPF and I was amazed to look at getting all the UI gimmicks I would love to with just XAML... thanks to the declarative programming model introduced with WPF.
On WCF, exposing an app as a service is just for a few configurations and you are done... I have been working with SOA kind of appa for quite sometime, with WCF it is become so easy...
Thank you MS, for giving us such a nice technology.