Continuous zoom approaches

I have a physical computing device that is basically an instrumented lazy susan.  I would like to use rotation to let me sweep through zoom from big blue marble down to cars in the driveway over 32,000 or so steps.  I realize Zoom levels are integers in the range 1-19 and Bing (and Google) provide not-especially-controllable animation between zoom levels. The tiled/pyramided imagery model precludes straightforward SetZoom using floats. I have seen suggestions for the Google Maps API for fudging viewport zooms between level changes but none seem to work very well. The Google Maps for Android has a camera model that can more or less do what I want but it involves running Android on PC hardware which is not yet terribly stable. Has anyone in the Bing Maps community found away to approximate continuous zoom? Did the v8 roll out add new features that would help?  Ideally I want to do this in Javascript but if I had to build a real Windows app I would.