I seriously doubt that PP would have the capacity and the only other company that has extensive expertience with dealing in prepainted miniatures is WizKids, almost everyone else went bust. The question becomes why would such companies do DDM? Isn't the market pretty flooded already with DDM? Isn't that the reason why WotC stopped with producing the miniatures in the first place, why would anyone be foolish enough to pick up such an expensive license to such an expensive productline when WotC has already poisoned the well?
Legendary Encounters sounded like fun almost three years ago, availability overseas has been lacking and there's only 25 different miniatures.
WizKids was going to start with MageKnight, that might be your best bet, they might survive on their own IP and CMG. There's also going to be a LotR CMG, that might be useful as well.
Rackham went belly up last year, but you might pick up a couple of cheap sets to use some as monsters/NPCs.
Dwarven forge is expensive and has only a few sets of prepainted miniature (skeletons and lizardmen).
There's a few odd miniature manufacturers that offer prepainted versions of their products, but those are usually only direct order companies.
You might have to buy your miniatures in plastic/metal/resin and get someone to paint them. Your best bet there is hunt up your local GW store and get one of the talented young painters to paint up some of your unpainted miniatures, might not be as cheap as some of the commons on ebay, but you have options ;-)
But what would you seriously want that WotC didn't release in the previous DDM sets? There's a seriously big secondary market, and if some of it dries up I'm sure WotC will fill in the hole with a DDM release, only non-collectable (as in the Beholder set).