I think people are comfortable with 1,000 life on hit (translating to 2,000 life per second for those with 2 attacks per second). But now that dual-wielding is becoming popular again, it's easy to stack 6% life steal. You can probably raise it further to 10%. Sticking with 6%, does a 35,000 damage per second (translating to 2,100 life per second) seem appealing for anyone?
On a side note, people are gearing with higher critical chance and damage builds. with that and the damage buffs from skills, I think life steal benefits the most from these.
Also, I think life steal weapons are still cheaper and haven't picked up yet.
Anyway, your thoughts? Also, feel free to correct my math if I assumed something wrong. ;)