Yeah it was in the newspapers about 6 months ago even though filming has just started now. I was reading this on Dark Horizons about when we will see our first view of the Joker:
"Of course the biggest question still remains - the new look of the Joker. Several sources say Warners plans to unveil it at this year's San Diego Comic Con in July, but the concern is that an out of context tabloid photo will appear first and so a shot may emerge even earlier than that.
A source for Batman on Film says that preliminary designs show him having "gray skin with lots of scarring" to encapsulate a general scarier look Nolan has planned. They add that the outfit will be "raggedy," like something he just threw together without stopping to make sure everything matched."
So it seems like we have only got a few months wait untill we get our first view of the Joker!