Looks neat and I think the community needs a working alternative to Sygic.
There are a few attempts going on, Marble, Modrana, Navit, Ovi maps script change but none (from my trials) offer a real commercial quality navigation alternative.
Would love to see a simple UI (look at TomTom and Sygic for examples), auto recalculate, offline maps, offline routing and voice navigation (doesn't need to speak the road names, just the usual in x metres takes the 3rd exit on the roundabout or take next left etc.

Ideally, would it be great if all the developers worked together and took the best from each app and made one killer navigation program.

Now, that would be community development!