This is the 4850
I'm looking at getting. The one thing I don't like about the 4800's is how hot they run. I've been looking for a dual slot 4850 that would vent air to the outside of the case like the 4870 does (per Q's recommendation) but haven't found any of those around and this looks like the closest I can come to an OEM over-cooled solution. If anybody has any better suggestions I'm open to hearing them.
On another note, I guess it's an expansion card design standard but I think it counterintuitive that single slot graphics cards have the cooling fan mounted so that it points down instead of up in a tower case. Heat rises right?