I have seen many serial entrepreneurs (who originally were developers) become very adept at the legal aspects of dealmaking. From this, I believe that cross-overs would not be too hard, but this assumes that one is drawn to things that lawyers do.

At the advanced level, the most important trait by far is good judgment that assures strategic thinking. If a lawyer lacks this, your deal will be in trouble. I assume your development project would also be in trouble as well without this trait.