The page transition animation would require you to do the whole front end development in Flash / Silverlight which would basically mean that you would use Sitefinity only for the administrative side. You would need to build your own controls and connect them to the data (probably through web services though I am not that familiar with either of the two technologies).
When we said Silverlight support, we meant adding more and more Silverlight controls (e.g. file upload which supports multiple uploads and drag-n-drop) and not reworking the whole system.
I am sorry if we have mislead you with our roadmap. Let us know if there is anything else we can do for you.
the Telerik team
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