Really looking forward to the goblin release, I'd expect them to sell just as well as the zombies (since people generally want hordes and hordes of the things). Sword/spear/bow goblins in plastic, along with a bolt/stone thrower kit would be the perfect initial release for them.
The bolt/stone thrower, could, with a bit of smart design even be usable with the dwarfs (completing 100% of their artillery options) if it had a generic chassis that goblin-themed and dwarf-themed front plates and extras were then added to.
A single goblin spear chukka from GW sold for £6 when it was released back in 2000. Now it costs £18.50. Generally people want 3-6 of them for their fantasy armies... that's one model where a mantic alternative would be very welcome indeed. Their basic goblins are still £1/model though, so I'd imagine that 50p/model would be the price point to aim for with the little guys, cramming as many on the sprue as possible. Looking at the size of the zombie sprue, there seems to be easily enough space on there for 5 goblins with seperate heads and spear/sword weapon arms as long as the legs and torso are kept 1-piece, and the command/ bow/ artillery get left for seperate tiny sprues. Same approach as the orc sprue, in other words, the new modular planning of the sprues is a much better idea.
Also, Seperate heads. Seperate heads. Seperate heads. Just in case the other hundred internet denizens making that same comment didn't shout loudly enough.
Stylistically, I have no doubts at all that mantic will massively knock GW out of the park. I mean seriously, just look at these monstrosities, they make the GW orcs look like well-proportioned truescale sculpts... some of the heads are so big you can't even see the bodies.