I have been using fleece as quilt backings for a long time--I do not use anything else as batting. Seems like everyone likes them. I do try to get the heavier weight fleece (you can generally tell by feeling the fleece) -- Walmart often has decent fleece on their sales, but you have to be careful because they always have a lot of very thin fleece on their sale racks too.

I'm going to have to try this. It seems the stores always have these big fleece sales, and I usually pass them up. Guess I should try it.