I'm going with Alpha Sapphire, but, as I always pick Mudkip, I am going to do something different for once and pick Treecko! He looks cool I guess, but I highly doubt he will ever better the legend that is Mudkip.
I actually don't know: I never played the originals, except for Emerald when I borrowed it from a friend when I was 5 and played it for like 3 days. Treeko is my favorite. But Torchic is pretty cool. And I'm pretty sure there is some basis on that whole "everybody lieks Mudkipz" thing. So Im neutral toward everything. Ill most likely just pick whatever when the actual game comes out.
If they all get megas and all of the stones are instantly available like Blastioinite was, then not Torchic. Probably the one with the best looks. Which I'm guessing will be ninja sceptile. So, I vote Treecko.
Grovyle is one of my favourite Hoenn Pokemon, even though I dislike Sceptile, so I'll probably go with Treecko. I'm hoping Sceptile gets a cool Mega with some arm-wings made of leaves or something like that so as to redeem the design.