only really 2 choices imo.
To "deserve" a push you can't just be some new talent, you have to prove you are worthy of it.
Its not a matter of "oh shes hot" or "shes wicked cool man" it's somthing you work to acheive.
I voted Natalya though as she has the pedigree and training needed to sucseed as a wrestler, not just a diva. And she isnt going to jump ship, or go off wrestling, its her life so wont waste a push.
my other choice would be victoria, as she has the skill AND has given alot to the show, she constantly makes a fool of herself and always stays in charactor. Shes like an experianced diva version of the miz. You will get what i mean when you watch her play the heel roll well, even when on the ring apron doing nothing shel keep it up.