Now that you've got the building blocks established on the Maemo5 platform, and brought Rapier 'back to life', you really have got us to a great launching point for developing a new GUI.
Regarding time - I am a pro SE, and I'm not getting paid for this, so I tend to squeeze my book-lernin' into lunches and evenings.
My thoughts regarding an 'attack plan' is to first spend some time exploring Qt and what I can do within the confines of the Maemo5/hildon environment....then (as Nathan suggested) start digging into BibleTime to see where a clean 'split' can be made (hopefully the code isn't so gnarly that this is impossible!). There should be a layer of code that deals with interacting with the Sword API - we can borrow heavily from this - and above this should be some presentation layer code that we can hopefully find a way to 'massage' into a new hildon-style GUI.
Everything I've just typed comes with the caveat "I'm a ***** and could be totally wrong"