Lovely minis...and i'm sure that they will sell well for those gamers out there with loads of Platoon 20 etc looking to go a bit zombie, but as others have already mentioned, 28mm is much more popular amonmgst zombie gamers.
Doesn't mean its a bad decision - afterall, you will corner the 20mm zombie market - its just that you'd sell loads of these in 28mm, as they are lovely sculpts, and in good generic shambling poses, meaning they have multi-buy appeal to a zed head like me.
Best Wishes
AKULA