OK, I'm still working on getting the tile-grid 'working' beyond a simple 2x2 fixed quadkey BUT that doesn't mean we can't play around with the display capabilities of a Silverlight-hosted map control.
No, there's no business application per-se for randomly animating, zooming and translating the map tiles like this, but it looks cool (view larger image)
[OT] BTW, apparently there are some element names that "just don't work", this being one of them:
<Storyboard x:Name="TimelineTranslate" RepeatBehavior="1x">. Had me confused for a minute when a SILVERLIGHT ERROR "TimelineTranslate has no properties" was thrown - but a simple name change and the animation worked.