Ive kept any eye on the game since its realse and have had many friends play the game, quite a few who i reguarly play different mmo's with.
The game could have done with another year or so in production to iron out the bugs and get the class balances right but it has not. Any mmo that comes out now ideally needs to be be 100% polished but hardly any games are.
Most MMO's will do well on their inital release, but a great mmo is how well it does 2/3 years down the line, the one big pull for TOR is its star wars, this will keep money coming in.
With Mythic and Bioware oddly they did the two parts of the game that each one is better at, Mythic did the pve when there better at multiplayer, while bioware is great for pve.
The level 50 cap is a restiction on the top level players, some chars need balancing, pve split between republic and empire certain storylines are stronger etc.
Overall the game will proably do well, as its firstly sold alot and has alot of money backing its future progress.