For single target heals (each row is normalized around haste on that specific row):
Code:
Spi Crit Mast Int Haste
Beacon burst 0 70 0 95 100
Beacon overall 25 95 0 135 100
Primary burst 0 55 95 95 100
Primary overall 530 430 680 1000 100
To sum it up, haste is good for beacon healing and burst. It is however horrible compared to any other stat for overall throughput on the primary target.
Haste also works very well with the current HR, something which will change in 4.3 where haste HR efficiency goes down the drain. Other changes in 4.3 includes spirit growing a lot stronger for overall throughput, and paladins becoming worse at healing the beacon due to the PotI change (nerfing the stats that are strong with beacon transfer).