Let's see...Dawn is essentially on the verge of suicide by this point, so giving her an abysmal loss would only push her off the deep end. Having Dawn vs. May would be every preteen fanboy's wet dream, and yet, I seriously doubt the writers would have a veteran like May lose to Dawn, who can still be considered a novice. Ash won't win, either, considering how contests aren't his deal (makes me shudder at the thought of further Zoey scoldings). As lame as this sounds, I think a likely scenario is a draw between Dawn and May. Not because the writers are too chicken to have one lead female come out above another, but because it would give Dawn a reason to give contests another try, even though realistically, May should easily crush her, especially with Hellspawn Squirtle/Wartortle.