Unless things have changed recently, I believed it was 24% for white hits when dual wielding for someone of same level?
At level 29 this would equate to 91 hit rating without any talents that increase hit. If you can gain any hit from pots/spells/talents etc then the conversion rate at 29 appears to be around 0.264% hit per 1 hit rating. Have a play around with Chardev.org to see the different changes to hit for different gear, etc..