Here is the latest toms article on the matter.
It is for the 965, 975 and 680i chipsets but will give you a good run down of their capabilities.
You can find more reviews of the various chipsets in the motherboard section of toms hardware.
Here is how I would brake it down for you.
If you want the best overclocks and SLI, go with a 680i based system like the Asus Striker Extream.
If you want a verry good overclocking board with slower crossfire support go with a 965 based system like the Asus P5b Delux.
If you want a decent overclocker with better crossfire support go with a 975 based system.
My personal recomendation would be the Asus P5B Delux with any of the C2D lineup.
I am assuming that you are planing on overclocking your cpu so get a good cooler when you order your system.