I played feral at 60 and loved it, but the expansion took away what I thought was the fun of the spec.
My account is frozen right now, but feral looks like it's worth trying out, especially after I've bored myself to death with resto for 3 seasons.
Flying through the air in cat form and spamming AOE bear mangle just looks fun. I can't wait to screw around with melee in duels using bear and cat charge to kite them around.
The addition of a snare is also huge for me, as I've always thought that lack of a snare held feral PvP back.
Here's the build I plan on using: http://wotlk.wowhead.com/?talent=0ZxGMsfbdbxRhIuVo0Eczb
Hope to see feral as a viable arena spec at 80.