I´ve heard these things:
* Air Minas is a new brazilian airlines which wants to start services ex Belo Horizonte with two ATR 42-300
* Nordeste will take most of Rio-Sul´s ERJ-145 while disposing of its current EMB-120 and Fokker F50 fleet.
* Estelar is a new airline in Colombia which wants to use ERJs (likely -145s) on domestic services.
* LAN Chile is rumoured to be interested in converting between 20 and 25 A320 options into firm orders.
* LAB - Lloyd Aero Boliviano is apparently interested in starting regional operations with Embraers, it is not clear if they will use turboprops or RJs.
* LAER has cheased operations, they had a fleet of two ATR 42-300 and 3 Jetstream J31.
Well, that´s all I know about at the moment. Fell free to post additional info...