I've been keeping tabs on any stats I see and calcing them myself, so here's what I have so far and my general thoughts competitively:
Hawlucha (Flying/Fighting)
Base 70/95/80/65/70/110
This thing's gonna be interesting. It has Unburdened and Limber as its abilities and has the new dual-typed move Flying Press, which is a Fighting-type attack that is also Flying-type. Being a Flying-type faster than the Base 108 Fighters with decent Flying-STAB is going to be big for it. It's also neutral to stealth rock, which is huge. It's just a tad under-powered and hasn't been confirmed to get any power-boosting moves as far as I know. It's also not stopping much with those defenses. Not quite Tomohawk, but it's not too bad.
Pangoro
Base 110/130/80/80/80/70
This guy is just a fixed Scrafty; and by fixed I mean it has an actual Attack stat. Mold Breaker could be cool with Parting Shot as it negate Clear Body and Magic Bounce. It has just enough Speed to run a Choice Scarf, which could be huge with Parting Shot.
Doublade
Base 60/110/150/55/50/30
This may not be the final evolution in this line, but it already has a couple impressive stats. The low speed is likely going to murder it with the new changes to Steel, most notably being slower than Tyranitar. Sacred Sword is a blessing for that situation but still the Speed is going to really test it. It has Autotomize for a +2 speed boost, but nowhere near enough speed for it to matter.
Mega Aerodactyl
Base 80/120/80/75/80/150
This one is a very mixed bag. The Speed/Defenses increase is welcomed, but the Attack in underwhelming and less than a Life Orb boost. This would be remedied by its new ability, Tough Claws, but that just raises another issue: Aerodactyl has next to no STAB contact moves. Fly is its strongest move that makes contact. Gen 6 may change this but, as of what we know now, Mega Aerodactyl isn't looking too hot.
MegaAbomasnow
90/135/95/150/95/30
Sporting stats that put Kyurem to shame, Mega Abomasnow comes in demanding authority sporting an incredible Base +58 boost to Special Attack (more power than Life Orb Abomasnow), boosted defenses and Snow Warning! It comes at the cost of a steep speed drop however. This thing was made for firing off Blizzards but can use powerful Giga Drains to keep healthy while Hail pelts the opponent for added damage. Very neat! (but also very ugly-looking) Mega Abomasnow might be just what hail needs. In fact, Abomasnow might be a really great Pokemon on its own without other weather abusers.
Tyrantrum
Base 95/125/120/80/60/75
May be decent in sand, but I can't imagine a metagame where this thing is used over Garchomp or even Haxorus.
Greninja (Water/Dark)
Base 80/90/75/100/75/120
We don't know much about its movepool at all, but it could make for an interesting Starmie alternative if it gets the goods.
Sliggoo
Base 60/70/50/90/120/65
Likely not its final evolution, but this thing is pretty interesting even this far. A Specially Defensive Dragon with Hydration. It seems to get the typical Dragon movepool with splashes of Water moves. Could be really neat on Rain teams as a dedicated Grass-type counter.
Mega Charizard X
78/130/120/120-130?/85/100
Everything but HP, SDef, and Speed were raise significantly. Aside from the defense increase, it still falls into what I explained in my last post. It's gonna be big in Sun teams.
Clawitzer
70/70/100/130/100/55
This guy's really banking on whether or not Hydro Pump is boosted by Mega Launcher. If it is, this guy's likely to be one of the hardest-hitting Water-type in the game with Choice Specs. Solid defenses and a pure Water-typing is gonna help too. Fingers crossed that is somehow nabs Aura Sphere or Focus Blast for Mega Launcher-boosted moves.
That's all I've got time for now. gtg