From the test server notes:
The Grease spell has been updated:
Covers the ground with a layer of slippery grease, forcing targets to make a Reflex save or fall. Grease slicks will sometimes be set ablaze by area of effect fire effects, dealing 2 to 12 damage per two caster levels fire damage to all enemies of the caster in the slick every few seconds, as well as the caster of the grease spell. A successful Reflex save will reduce this damage by half. Slicks that have been set ablaze will quickly burn away."
Even more potential for the best spell in the game!