Just a couple of thoughts.
Stomper ArmyAre the Mega-Dreads really necessary? Seems like they're just Stompas in essence? What's the differentiation in a battlefield role? Or is this just another "It's in 40K" addition? That's not a personal swipe, I have the same issue with every Land Raider/Dreadnought/Etc thing that comes down the pipe, that doesn't have a distinctive battlefield role change, or at the least, an official model (why I'm not as irked by Razorbacks and the two categories of Marine Dreadnoughts).
Is the Mekboy Stompa supposed to have all the primary weapons, or just one? And no option for a Kustom SawBlade?
Grotling ArmyI really want to try the Grotling army, though I'm not sure I've got sufficient figures to do it justice. It's a shame they don't have some form of silly clown car transport option (Battlewagons that carry 1 Boyz/4 Grotz, but must make a DT test if it moves more than once in an action, or moves more than half in a move).
Also, I think the SunTzork Strategy Rating should be d3. He's supposed to want to be the smartest. So sometimes, he should have some cunning plan. Rolled either before the game, or any time it comes up. Either could work. It's not like the army's gonna actually win or anything.
Speed Freak ArmyIs the new Speed Freak army supposed to be identical to the old Speed Freak army with a few cosmetic changes? Cost of Nobz Bikers, and where they can be added being the only two changes I can see.
Blood Axe ArmyI think the two Lobba units could go to 60cm range without much problem. At 45cm, I just can't see passing up a Big Gun option.
Shouldn't this army have a more iconic Kommando unit? Either a 0-1, or just plain make the standard Ork Warband 2N+2G+6Kommando with the appropriate price difference. When I think Blood Axe, I think Kommando. And just throwing them in as a minor formation seems like a wasted opportunity.
That's just the stuff off the top of my head.
Morgan Vening