The Oompa Loompa Kemobi debate and various permutations of the Emperor's hologram seem well covered, so i thought I would add a couple of ideas.
A couple of things I considered mocking up, thought I would get some reaction first:
* The Executor and her fleet would most certainly be visible from the ground, as DS II was in Jedi. It would be cool to see them from the POV of a ground pounder.
* Every time a transport launched it had x-wings escorting it. It always seemed to me the X-wings might have shot at targets of opportunity (read AT-ATs) as they left the rebel base. This would be another way to expand the scope of the Hoth battle. it would require a new sequence, and maybe some 3d model work, but it would be amazing to see Red flight put torpedos into an AT-AT.