Here's some info I dug up on the forums while bored at work:
I found out where the new 6 man dungeons, 3 man dungeons and 12 man are
the 3 man ones are in Mirobel (Eregion, Southwest side of the zone)
"They drop from 2 other 6 man instances in Moria. You have 6 hard mode instances, 4 dropping barter coins for set items and the others dropping the barter coins for non-set items (with radiance).
Level 54-56: Forgotten Treasury in the Silvertine Lodes
1. Level 58-60: Grand Stair in Redhorn Lodes
2. Level 60: 16th Hall in the southern Redhorn Lodes
3. Level 60: Fil Gashan in the Flaming Deeps
4. Level 60: Forges of Khazad-Dhum in the Flaming Deeps
5. Level 60: Skumfil in the Foundations of Stone
6. Level 60: Dark Delvings in the Foundations of Stone
The last 6 all have a hard mode to them, that when completed drop a barter coin for radiance gear. 4 of them are for the raid set, while the other 2 are for non-raid set radiance gear. I'd assume, then, that the last 2 raid set items drop from the watcher so...
7. Vile Maw in The Waterworks (12 man)
Have fun ;) "
Apparently there is a way to do some on hard mode versus normal mode too. Similar to WoW's heroic mode I imagine, though not quite as insane maybe. -Thallian