I understand both sides of the issue and I would like to see a compromise. As previously stated, I would like to see a trial period to level 15 or until you complete your final class mission of the capital world. Just a small taste of what's to come before you make a final decision would be a great benefit.
For those of you who don't want to feel they have wasted their time playing both AC's, well, I also don't want to feel like I have wasted my time leveling up an AC that I'm not enjoying. In most MMOs, I can try a different class and get a basic feel for it in the first few levels. here, I must level to 10 before I can get a feel for the class. My main toon, I recreated a few times because I was flip flopping between ACs. I finally decided on Sith Sorcerer (on a side note I'm absolutely SICK of Korriban). What I have found myself doing for alts now is, playing 2 toons up to level 10 on a different server to test out each AC. Then, on my main server, I can choose the AC I enjoy most. To me, this is an absolute waste of my time, but I'd rather spend a few hours now then feel like my entire time to 50 is a waste. I absolutely agree an AC switch at 50 is bad idea. Having a trial period available to try out each AC I think would satisfy the player base enough, without causing too much turmoil among those who don't want it.
Everyone compares this to WoW, but this is not WoW. And this is not EverQuest 2 either, but I'm going to compare it to that as it's a bit more relative. EQ2 tried this tiered class structure at first too. To start, you had 4 archetypes: Fighter, Scout, Priest, Mage. At level 10 you then choose your class, (3 choices) and at level 20 you then chose your sub-class (2 choices) resulting in 24 different class possibilities. Just like SWTOR, the class structuring caused people to request the ability to change their class/subclass. And just like SWOTR, there was the argument among the players as to why or why not changes should be allowed. Eventually, the class tree structure was removed from the game, and EQ2 now has you choose your primary class at character creation.
Due to the way SWTOR is designed, I think starting at level 1 isn't the right idea, but I do feel that a trial period would be a nice compromise so that NO ONE feels that they have wasted time playing.