Might I suggest sending Veriant emails, sending feedback ingame, and even
petitioning about this, it has been unannounced, therefor a bug in my book.
Even if they intended in this change, it should be changed back. It's
insane green mob's should resist at all, let alone what we deal with after
the patch. So let them know, tell em you want it the way it was.
FYI, they also reduced the damage (to mana) from mana sieve GREATLY! Before
the patch, it would totally drain a lvl 39 wizard to out of mana. Now, it
takes a total of 4 cast to do the same. Also, the effect would last 3 to 5
min. preventing them from meditating in that time. Now they can meditate
right off. Once again, these changes were not announced, therefor a bug and
if not, it should be changed back to the way it was, or least made stronger
than it is after the patch.

Telan Ka`Rlaah