Heirlooms in Cataclysm

[High-five]

WTB Trade in solution for the 8 full sets of heirloom gear i currently have...

The new heirlooms are cloaks and head slots, NOT new chest and shoulders. They are meant to go WITH the old heirlooms. Blizzard doesn't want us blowing through the new content that they have been working on for YEARS. Who knows, maybe after Cata has been out for several months or a year, they may allow old heirlooms to scale to 85.

So no, you can't trade them in, save them for a new alt. I highly doubt anything we say will change that.

[Correlia]

Blue post from a few month's ago states that the current BoA gear will stop scaling when you hit 80 BUT there will be new BoA gear to buy at 85 that do scale to lvl 85.