Melee would be a great idea.

The possibility of stealth kills or even hand to hand combat could be very useful.. Especially in those Stratis life servers. Civilians can't DO anything but run and shoot.

Another thing; if there was a way to holster weapons that would be awesome. I'm sure that what I am asking is a little bit overwhelming, but I believe a lot of people would agree that these small elements would make the game that much more enjoyable.