They did do the JP to gold conversion a few weeks ago. You only got gold for any JPs over 4000 that you had. My younger sister still hasn't grasped the concept of actually using JP/VP to buy gear, so she got 1200g in the mail.
As for the level 80 heroics, the honor points are because of the Essence of Wintergrasp buff that used to award some kind of currency when your faction controlled WG. I'm not sure about the JP side of things, because the only lvl 80 heroic I'd been running recently was Utgarde Pinnacle, but I only kill one boss (Skadi) and I've been JP capped since 5.0.4 and can't remember if he gave JP before that. So, in short, I'm not much help!