Arena points were reset after this latest update. This basically puts even the Warlords on equal footing right now with noobs. However a sad side-effect is that if, like me you were a high enough level to buy trophies and didn't take the chance to do it you'll be working your way back up the ladder for a long long time before you qualify for that trophy again.
That sounds bad but there is a signficant upside! All those chain stunners that made the arena absolutely unbearable will have to start from the beginning as well. Now with Ice Wizards having a stun shield I think the arena scene will change and ice wizard will be in demand to combat stunners.
Have fun out there!