Yeah, I worry about that too. As a shorter guy I'm thinking of doing Toshiro Hitsugaia from Bleach, but Bleach cosplay is both overdone and kind of plain. In the end all that matters is if you're having fun. People will still want to take your picture and you can enjoy an afternoon or more of escapism!
So yeah, do Haruhi!
Black Star (Soul Eater): Wizard World New Orleans, November/December 2012