I haven't been able to find any documentation on this, so I'm coming here to ask. I recently leveled a spacegoat Shaman and before the Tuesday, Nov. 23 patch, I was well on my way into several heroics. Hell, she even got achievements that my main doesn't have yet. I've done about 30 heroic instances, all using the lfg tool. I earned enough JP to buy shoulders. Wooo go me, I was well on my way to being prepared for Cata.
Now, however, I can't queue for heroics. It says I need a higher average item level and that my current is only 156. Admittedly, I am still using the heirloom chest, staff, and one trinket. I realize those count as item level 1. My problem is that there's no documentation that they were either increasing the minimum average item level required or were going to calculate heirlooms differently. It's a problem now that I can't gear up my shaman for Cataclysm. I got her to 80 before the Shattering, it'd be a shame to not be able to take her into the new content fully prepared.
I submitted a ticket to Blizzard and of course, got the standard reply: reset your UI. So, I did. Didn't change a damn thing. I submitted a ticket again and am still waiting on the reply.