Don't be a Moaning Minnie! I'm left-handed and have spent my entire life adapting. I expect game avatars to be right-handed and adjust myself accordingly. Never had a problem. Never set up the mouse for left-handed either. Tried it once at my boss's insistence and it buggered up my work-rate on the spreadsheets I was using.
You want a problem in gaming to grumble about? Try localisation for English-speaking countries! Everybody else gets their own language, but we Brits (and Canadians and Australis, I bet) have to put up with the abomination that is American 'English'!
Seriously, would it cost that much, or be so terrible, for Commander Shepard or Kratos to be able to speak British orAustralian English? Or does the idea that Shepard might have trained at Sandhurst rather then West Point infllct erectile dysfunction on the American male?