I have, however, come to realize that navigation through a large project with keys alone is suboptimal. One typo in a nav command and you have to press at least four or five more keys. With the mouse, you're less likely to make such mistakes and your retry time would also be low. It'd be like trying to browse the web using the keyboard alone... even I, a hardcore vim user, found firefox/vimperator underwhelming to say the least.
What would be awesome is if they made some sort of hybrid superintelligent keyboard where the whole keyboard surface could also act as sort of a multi-touchpad. As a compromise, I've found that the thinkpad-style pointing stick in the middle of the keyboard does a fair job.