I'll try to address the WPF/SL part of the story.
Let me start with the WPF release plan. We are busy right now shipping our first official release of the WPF control suite. The suite will contain the following controls: grid, carousel, calendar, date picker, numeric input box, treeview, slider, progressbar, panelbar. Right now we are in the middle of our last sprint
, and the release will go live with Telerik's Q2 release due by the end of the month. RadControls for WPF will be included in the controls bundle.
As far as Silverlight is concerned, we will be officially releasing the suite shortly *after* Microsoft ships the official version of the plugin. We expect that to happen by the end of the summer. By the end of we will have a public preview build that will let you and others play with the controls, get a taste of what's coming and have the chance to provide feedback.
The Q2 release will contain another goodie. We call it the WPF "Futures" build. It will contain preview versions of our WPF Chart, Gauges, and Scheduler components. Those components are still "work in progress", but having them publicly available will allow us to check with customers if we are going in the right direction. The Chart, Gauges, and Scheduler components are planned to be released officially later this year -- with our Q3 release.
the Telerik WPF team