Ironically, this is an advantage of Kindle. The last time I checked, Kindle DRM was relatively easy to get rid of. I didn't research as exhaustively because I wasn't very interested, but it seemed like non-Kindle formats were harder to deal with.
The Kindle format actually is Mobipocket underneath, but with an algorithm layered on top that converts a Kindle serial number into a Mobipocket ID. Needless to say that algorithm has been leaked.
