I got my fingers crossed, but overall, I really finally want to see a Twilight sneeze. She needs one.
Oh.... and a great storyline this season.
I kinda doubt at this point they'll make her. She's all princessy now.
This is something I've thought of as well. The producers certainly wouldn't want to make the princesses sneeze. It just wouldn't seem... "regal", I guess.
So,
IF that's the case, Twilight could possibly never sneeze on the show, now that she's a princess.
HOWEVER, if that's not the case, it could simply be that the producers haven't made them sneeze yet.