The ability to toggle OFF armoursuits visually. They can still be ON, but it's invisible armor the same way you can make your helm invisible in WoW. A lot of us spent a decent amount of time creating our own uniform variants for ourselves and bridge crew. Uniforms that go away the moment you put on an armoursuit. We should be able to toggle that off, n'cest pas?
A mirror universe imperial commbadge. I wouldn't be surprised if this was already planned as lootable, or as part of a Mirror Universe Uniform set in the CStore to conincide with a Mirror universe event.
Speaking of which... will there be holiday events in STO?