i think the real new application of the hate meter will be more for stealing hate than not getting it. Stealing hate is a very useful concept. you can take hate for a few hits, or when you have certain buffs, and others can take it back. an archer could go over hate and bind in tough situation, then tank could get it back before bind wears.

That said, they said it will be a shown as a % of whoevers tanking agro, so you wont really have exact numbers, you will still have to have a good idea of how much hate they have, 80% of the hate of a glad or 80% of the hate of the mage are two totally different numbers, also that % should fluctuate a lot so it wont be THAT safe