Here's some info on new Hyjal loots:

Trash mobs in Hyjal now give rep (3 per mob and 200 per boss)and items (new epics, heart of darkness, mark of the illidari), more hyjal loot will be added to this news.

Black Temple and Hyjal trash mobs share the same loot table with a few new items.

"For those of you that arent aware you now receive less rep for a full clear without wipes." mek

Reputation gain:
- 3 rep per trash mob
- 15 rep per frostwyrm
- 200 rep per boss
- 500 rep for Archimonde