Now this is something that really bugs me. Heroic instances are a regular part of life for many (most?) level 70s; they’re the next step after gearing up at 70, and provide a good transition between standard instances and raids. There are heroic versions of every TBC dungeon, from Hellfire Ramparts through to Shattered Halls and Arcatraz.
Unfortunately, the loot is a little imbalanced. Heroic versions of pre-70 dungeons (ie Hellfire Ramparts, Blood Furnace, Slave Pens, Underbog, Mana-Tombs, Auchenai Crypts, Old Hillsbrad, and Sethekk Halls) have all-new loot tables on every boss; the early bosses will drop a level 70 blue item (iLevel 115), with a chance to drop an epic gem, while the final boss will drop similar stuff and a nice Heroic-level epic (iLevel 110). (And every boss drops a Badge of Justice.)
Heroic versions of level 70 dungeons, however, are a bit different. (ie Shadow Labyrinth, Black Morass, Steamvault, Shattered Halls, Mechanar, Botanica and Arcatraz.) The final boss has the same sort of tasty loot tables as the final bosses in other Heroics, but the earlier bosses have exactly the same loot tables as they do in Normal-mode versions of the instance! The only difference is that they have a chance to drop an epic gem, and they drop a Badge of Justice.
This has always felt like a real gyp to me. Heroic dungeons are not easy until you’re fairly well geared, and when you’re running them to try and gear up (rather than just farming them for badges and nethers) it feels like a total ripoff to slog your ass off to a boss, often dealing with brutal trash on the way… only to get just the same junk you’d get from a Normal-mode run of the instance. It makes PuGs a particularly dicey proposition; if you’re not confident that your group is going to go the distance to the final boss, there’s almost no point in starting.
It’s not a huge deal, but I do hope that if Blizzard retains the Heroic-mode concept for WotLK, the Heroic versions of level 80 dungeons will have more generous loot tables.