Most of us know now that the Emblem Editor is returning with improvement. At the time of posting this, whats improved is unknown, and the following ideas may already be implemented, but I'm putting them out there, just incase.
Full Colour Selection - Black Ops had a fixed colour palette, and although it was a decent selection, I think the option to use any colour would be a nice addition. Perhaps a colour wheel could be added (like this) and controlled via an analog stick for the wheel, and up and down arrows to adjust how dark the colour is. To prevent these control interfering the normal layer editor controls, a new "window" could be opened when pressing a button (e.g. circle/B) to pick the colour at the edit layer "window". I'm sure there's a better way of implementing full colour selection, but this is just an idea.
Eraser - The option to use any shape as an eraser would be really cool. e.g. You have a red square, and you want to cut out a smaller square from the larger square. Then, place a smaller square in a layer above, press a button to change the layer type to erase - everthing below this layer will be "cut" with respect to the shape - and you have a red square ring. This is a simple example, but this ability has a lot of uses.
Merge Layers - Not much to explain here. Being able to merge two layers into one is so simple yet incredibly powerful and theoretically allow infinite layers.
The main feature that would be really useful is to merge layers. We could see some really amazing emblem creations with this option.
Hopefully the developers see this post too.
Thanks for reading.
(To those who say that Black Ops 2 is an FPS game, and not an art game, so it doesn't really need an emblem editor, or its a waste of time, etc., well.. if you don't like it, don't use it. )