[Tidus810]

Hmmm, interesting topic. I'm left-handed, but my hands are kinda quirky.
Specifically, my left hand is very strong with consistency-based patterns, like the jump chains in Mario Minor or Radio Heads. However, my right hand is much better with long trills (see: Blooddrunk). As for rolls, I'm much more confident and better at left to right.
As for patterns that cross between hands, like 1-3 trills, I haven't really found any preference... I'm pretty sure my left middle finger just sucks, actually. :S