I love the fact that they decided to mirror the classes so much in SWTOR, not only does it help with balance it also adds the possibility of future good times with the lightside/darkside system. Think about it, say a year or two down the line people decide they want to switch sides they should fully and easily be able to.
Just add a series of quests on either side for each class that can turn them from Empire to Republic or vice versa. Make it a one time for that character only… as in once you switch that’s it. no jumping back and forth. I mean who is to say the Empire doesnt recruit some Smugglers as Agents or how the Jedi Order turned that Sith Marauder into a Jedi Sentinel. I know it might add some confusion to people with not the normal races being specific classes but it could be fun and add a whole new element to the game, or even add that spark of freshness a game sometimes needs around a year old.
Just an idea bouncing in my head. I know if it was an option i would try it on at least one character for the storyline value alone as I know Bioware would do a good job on it as so far I am in love with all the stories in this game. Something that could be free content or even something with an expansion, who knows. If done well enough I would pay for something like that added to the game.
-Cortical
Cortical Scrub 
I loved that you could change your side in EQ2 after doing a bunch of nasty quests. I always wished WoW did that. I hope SWTOR thinks about it, but I doubt it.
Of all the games SWTOR lends itself the best to that. Hell i have done multiple quests with defectors and shit. For now its not a great idea but definately a year or so down the road when people might need change in the game. Only time will tell 🙂