Just like with the other ratings, the values listed here equal 1% for that characterlevel.

At 70, you will need 15.77 haste rating for 1% haste, not 10.51; i suppose this will be corrected here in the future.

For each 15,77 haste rating you will get 1% more of your base attacks per second. Lets say you are a Rogue with a 2,6s Weapon. 2,6s means 0,38 attacks per second, with slice and dice up you will get 30% more, 0,38*1,3=0,49 attacks per second, which is 2,02s speed. If you added 158 haste rating on your gear with the same weapon you would get 0,38*1,4=0.53 attacks per second or 1,88s speed. The factor 1,4 is just the 30% from s&d added to the 10% rating gain plus 1 for the formula.