Dar es Salaam to Nampula - Good idea?

[kuntushi]

Basically want to follow the coast down, pass Mtwara, cross the river & border there (seems possible, not sure about getting visas though) and keep going to Pemba. From there we'd go more south to hook up with the highway at Nampula and head west to southern Malawi.

If this seems to difficult, the only other option is to just go to northern Malawi and drive through it. Doesn't seem as fun But we'd rather miss out on some fun than be stuck in eastern Tanzania for weeks.

Are there any recent updates on the road quality and/or border crossing at that river? I know a bridge is going up, but haven't heard much about officials being there for visas, etc. Do people even think that route is a good idea?