Not sure how big of a market exists for 'em, but since I already own and enjoy several Marvel, DC, and LotR Minimates, personally I say BRING 'EM ON!
I'd actually MUCH prefer to see good mini Battle Scale Figures done instead. About the same scale as the botched Mattel ones, but conceptually like the LotR: Armies of Middle Earth figures. That way we could get all the characters, giants, vehicles, beasts, castles, environments and so on in scale and fairly affordable.
Can you imagine the battle scenes??!!