Fantasy=Sci-fi

Jumping off the Surfing Elf idea, and watching Thor, is it so far-fetched to consider a galaxy where every fantasy species (elves, dwarves, trolls, mermen, dragons, etc.) had their own planet? The Dragonriders of Pern played with it decades ago: a planet colonized by humans, domesticating the native dragons to burn space spores before they devour the planet. As Thor described, magic and science are the same. Asgard, Midgard, Jotunheim and the rest are in fact planets across the galaxy which are accessed by the wormhole technology, Bifrost. Why not completely blur the lines between high fantasy and hard science fiction completely? Humans colonizing planets and coming into conflict with other planetary and/or dimentional lifeforms, all of which parallels with ancient folklore.