I've had this problem as well. I tried to get on early before work this morning (and before the down time for the patch) but it was frozen. I waited for about five minutes, and it finally 'appeared' to begin to work, but instead of taking me to the character screen it took me to the server selection screen and had no visible servers to choose from. I noticed AVG updated. I tried again after I installed the SWTOR update this evening and still had the same issue, so I disabled my AVG protection for five minutes and I was able to get in with no problems. It's reactivated now, and the game is still running fine. Guessing the AVG update screwed something up.