I don't think I've read it anywhere. If the customization will be as good (if not better) as they showed, it shouldn't be difficult for them to implement this "switch-hand" feature. Check their forums for any suggestion on that topic. If there is none, create one.
Does anyone have a clue if we will be able to choose the hand we hold our weapon on? I as a lefty would like a more realistic experience with my left hand as my "trigger hand"...