Quoted directly from Massively.com from link Quarion posted on the front page of the forums!
"Turbine wanted to faithfully recreate some D&D spells, but not all of them could make the cut-- Earthquake was listed as one that they "had to pull at the last minute because we just couldn't get the experience quite right. But we hope to bring it back in future modules."
God I so hope this is true, would love to see that spell for module 7, or if they ARE going to delay 6 (work the kinks out of this spell!! You will make a lot of people veerrrry happy!)