Wow tanks must hate you.
In my experience, DPS should focus down Weak -> Normal -> Strong -> Elite -> Champion.
For every mob the DPS kill, it's one less that the tank has to hold onto. It's FAR easier for a tank to jump in and hold the biggest baddest of the group, while the DPS pick off the weaker mobs fast, then everyone focuses on the Elites/Champion.
That is like... DPS 101
Agreed.... AOE down little mobs first or if no AOE single target them. They tend to be the ones going after the healer since if there is no DPS on them it is much harder for the tank to hold them causing the healer to get aggro from heals. This is especially important if you have a Guardian/Juggernaut tank with more limited group aggro abilities.
The kill order of course gets modified situationally. Non-CCed healer mobs go down first unless there is some very situational need to take something else down.
DPS that insist on ignoring the little guys to get the "big guy down" deserve a vote kick.