Maria. She can overpower Henin and she was extremely consistent in early 2008 (so Henin's scrappy defense wouldn't be as big of an issue). Henin would have a hard time on Sharapova's serve and Sharapova would have looks at breaking Henin. It'd be a tight match but the difference would be that Maria could rely on her serve all the way through the match and Henin would be under so much pressure due to the Russian's weight of shot. That's my take anyway.