Does anyone know an example of feeding DeepZoom control from the database, not from the file system?
So my initial thoughts on this were you'd probably need to write your own MultiScaleTileSource which returns tiles from a source other than the file system.
Quick Google on that subject has thrown up this article which looks to be exactly what you're after: http://www.codeproject.com/KB/silverlight/DatabaseDeepZoom.aspx