This sucks. A lot.

It's a relative buff to rogues/warriors since it essentially nerfs all classes with mana pools.

I don't think blizzard understands what a big nerf it is to us.

On my druid:
no more rank 1 motw, thorns, and rejuv to cover innervate, or to act as dispel fodder on myself/ally.
no more rank 1 moonfire, faerie fire, insect swarm to act as dispel fodder on enemies.
no more rank 1 roots... now I have to spend 300 mana more for 50 more damage. Woo hoo!

For mages (I don't have one)
no more rank 1 AE to pull rogues out of stealth... nope now you've got to spend 100s more mana.
no more rank 1 FBs to slow enemies
no more rank 1 novas (who cares about 100 more damage for 100 mana?!)
no more rank 1 sheep

For healers (esp paladin/priest/shaman) no more downranking to prevent over heals.

the list goes on...