An HeliumReborn-like UI would be awsome. Simple, desktop fashioned, self explanatory icons, no obscure gesture-based actions to do simple things. I really hate these "touch friendly" UIs where everything has to be totally different from desktop UIs (with non self-explanatory icons or gestures) with all buttons hidden by default unless you tap somewhere to make them appear. I mean there is enough space on the screen to show basic buttons and avoid the Mobile Firefox UI. MicroB UI was great, it gathered the best of both worlds. Helium UI has some similar pros.

Whatever the UI, keep up the great work Romaxa!