We, PzU are still plodding away at the MMP mod, we have a pretty stable version of multiplayer now. We often have 6-10 beta testers all in game and don't have many issues now.
Just this week we have managed to fix one of the major annoyance of TvT in mp. The ability of other players to see you behind hills at distance. This was due to terrain lod'ing and after speaking to one of the Russian dev's, we were told it was hard coded. We have managed to side step that and now have it working as you would expect.
Underneath the center cross hair is a commander in the Tiger turned out, this was never possible in MP as the whole tank would be visible at this distance.