Issues with the game as it stands are far more important to players than 'boosters' & 'expansions' that are extra cost you should get a good core game then develop it and tweak it. Do not develop new stuff and exclude problems in game now.
Funcom is up against the clock with SWG just around the corner, if the game is even close to AO people will go and play it because its 'Star Wars'.
As it stands I wont be buying either booster or expansion pack, ill play AO as it is and some WC3 and then probably move to a new game.