KOTOR2 already has this as feature after a fashion. Additional lines open up after a certain amount of games are played - I forget the amount - but you can always change the number manually by editing the INI file.
Those wishing to contact me, please do so using Deadly Stream's PM system. I am rarely on this site anymore.
Considering trying out (or returning to) SWTOR? You may as well go through my link
and help get me some SWTOR referral points!