Hey... since I saw this thread I've been wondering if there was such a product!
The aim would be to reduce reflections from the floor, right?
Recently, we've seen acoustic drapes (seriously, from a serious company). Perhaps such fabric could be used as an underlay for a more decorative top mat.
I suppose there is a danger the room could become too dead.
If I had a dedicated room, and the budget, I really would love to play with stuff like this.