I think the only difference is rev2 provides "a 100% solid capacitor design for greater stability when overclocking."
Other than that I'm not too sure. If you're considering buying one you might want to look at the 965P-DS3P (P stands for Pro) which has more features than the DS3, such as CrossFire support and firewire I believe. Although it is a little bit more expensive but not as expensive as the 965P-DQ6, which only provides better cooling if I'm not mistaken.
thanks for your reply but i believe they both (DS3 Rev1 & Rev2) have 100% solid state caps its the S3 that doesnt on the face of it, it appears they're more or less the same perhaps its more to do with the software or perhaps they've updated some hardware i just cannot find a review of the DS3 rev2 to be sure so if anyone has the DS3 Rev2 and has noticed a difference or has read a review and can give me the link i will be very grateful.
However I should be picking up the board tomorrow so i will post any differences i find when building with this board at the end of the month.