can someone explain to me the new party exp thing?

If they don't deal damage to the monsters they would now be getting about half of what they got before.

so being used as a HS mule for leeching has been rendered obsolete, right?
and @Cyanne:
so now, if i am interpreting this right, you receive more exp if you deal more damage, and less if youre a lower level than someone else in your party, or more for the latter?