With the Shb enmity/tank stance changes regen should no longer be a problem, as long as Tank and Healer know what they are doing:
Tank: has to hit all mobs with aoe/or any attack before running to the next grp of mobs (when doing big pulls)
Healer: has to stick to the tanks ass, so the tank can pull any mobs of the healer with a simple aoe attack.

If the healer gets aggro and runs away -> bad healer
If the tank doesn´t hit all mobs -> bad tank