I enjoyed reading Jaime Rodriguez’s thoughts on the Silverlight news from MIX 09. Very good info; however, I still think that most WPF apps will begin moving to Silverlight unless those additional features are needed. In most layered architectures, workflows, et. al. are created and used in the service layer, not the presentation layer. Silverlight as Moonlight is also the only option for Mono compiled apps, and I don’t believe the Mono Project plans on adding WPF in full. So for complete cross-platform re-use, you’ll need to stick to Silverlight.