Personally I think he will have 2 of the starters (A la DP) so I think Litten as it seems exaclty the kind of 'cute' starter that fits the female lead so ash doesn't catch it.
Also, you think the main female character of SM will be Ash's companion? Or maybe just a Gym leader like BW?
I don't really mind who becomes the female character so long as they give her a story as well developed as those we got with May and Dawn. The new girl doesn't have to do contests, just have a storyline way above the quality given to Iris and Serena.