On smart-phones (5" screen or smaller):
-Ability to display a bank of fader in vertical view. Actually, on my Galaxy Notes 2 and 4, CICPro can only displayed on horizontal mode so on mixer view, it displayed some tracks but shorter than if it is displayed vertically. Precision could be better in this display mode.
On tablets (10" screen):
-Ability to display the mixer view on the totality of the screen to have the same precision as described upper.
Both types of devices:
-Ability of arrangement view to control the position of the cursor while Cubase is playing, not only while Cubase is paused. It could be a perfect scrolling/scrubing/positioning function.
-Ability to display plugins control panel. Not necessarily with the same GUI as the original, but, why not, with a generic one.
-Ability to tweak our own control panels for each of our VSTi/fx. 
A sort of Lémur inside ;op
-Integration of “e” mode of a track (I don’t know English name of its screen mode on Cubase that display all like Insert/Channel Strip/EQ/Sends/Fader/etc…)
-Ability to replace text on each button of the Key Commands mode by icons.
-Ability to have audio Master bus return.
-Adding Punch In/Out button on the transport bar.
PS: Sorry for my bad English. Hope you’ll understand all my post. :-/