It could, but it would be incredibly hard to get the two magnets' strength correct (you need two, preferably more on the sides- and then you couldn't see anything.) You could, alternatively take a strongly paramagnetic substance and put a ludicrously powerful magnet under it and the substance would float. Unfortunately, paramagnetism is incredibly weak so don't plan on finding uses for it. Also it could only float like an inch, and even then that would require something very light.
I never said it wouldn't be difficult. If you got two very strong magnets and placed them a few inches apart, each would generate a sphere of magnetic field and at the upper intersection of them it may be possible to place the ferrofluid to have it maintain position.
EDIT: On second thought the world is three dimensional and you may need a third magnet placed equidistant from the center of the other two, then at the location of the intersection of all 3 there should be a pocket where you can place the fluid.
