From what I can tell it now removes all concealment (friends, foes and caster) including racial blur, class concealment, and even concealment due to darkness.- Attempt made to make invis purge do something. Remember, it's an AoE centered on caster, not a continuing aura.
This spell wasn't used much before but is even less likely to be used now. Before this change I had seen players use this spell to get rid of Improved Invisiblity while retaining some other form of concealment for themselves.
Since this spell is not party friendly using it tends to bring some harsh words from your teammates and now since you can't even have some other form of concealment to back it up I believe this spell will become absolete to players.
Perhaps allowing this spell to only effect enemies would make it more usefull and you would see alot less concealment retained in PvP battles because of it. Which would also make spells like Improved Invisibility hold less importance.