I really like this idea too. I haven't done any decomping until i wanted to up my level 75 gears, but it really does get annoying doing it one by one, especially when i come back to town, sometimes with 75+ items to decomp! Talk about slow! Even if it could be increased from one slot to, say, 5 or 10 (25 would rock but i wont hold me breath). It seems the loots it gives (color of stones, amount, coins, etc) is random and only dictated by level of item, so it shouldn't pose any problem with the rewards.
On this topic, it would also be great if ALL blue items can be decomposed. They all say they can be disassembled in the discription, but I come across a lot of them than can't. Cheers XD