http://www.rpgnow.com/product/103952/My ... rom_home=1
Here is a product, which if you could take it as an example of a great product. I see products like Whitewolf put out or this one where they take classic non-copywrite concepts, like 'a goblin' and then do a take on it. Research the creature and go for it.
This will potentially alter the classic D&D take on it. Much like we see a Red Headed Thor and how he is classically described is different than the Marvel THOR.
Yet, having viking, and other cultures like iceland, finland, etc. and their related mythos (the Finnish mythos is different from the Norse as you know already as you, like everyone, have read the Deities and Demigods).
think: Mythic Earth, fantastic creatures that can be met in modern Earth potentially sort of like the movie Big Trouble in Little China. That is the approach I think works very well for MnM3e.
Could a more truly 'fantasy' setting work too? Sure but that should not be the default assumption. It could be, like we see with GR's take where they have a full on fantasy city (their freeport setting) that you can go to via a place like Freedom City via some magical means.
Just like you could have post-apocalyptic creatures that exist in some 'dark future' like we see in various comic book timelines. They generally have a mythic earth approach if you go back into DC comics I'm sure you can actually meet Merlin and encounter some fantastic creatures.
That is what appeals to me, and I bet you many others. Do the hard work first, then worry about art and such. If the product is less cost, and not 'purdy' but has the meat on the bone the pretty art is secondary. Of course, it can make it a premium product.
Concentrate on stats, not oodles of fluffy text. Put in some scenerio ideas for a creature or options so the GM has food for thought. It could end up as a very useful guide.
Once your done, if you can gain the art, stick it in there but the true value for someone like me is not that, its the write ups and ideas.