Paladin MT. Threat and damage meters present.

Short overview of bosses there, don't want to spoil too much, but it will give you an idea about dmg we receive and threat paladin tanks produce.
Extended footage of Heigan and 4 Horsemen encounetrs.

Difficulty-wise, hard to say. Almost everyone in group had Naxx cleared pre-TBC, so it's very easy... But I think that was intention for this entry-level dungeon.

You can check my 2 years old video from same place to compare :>
http://warcraftmovies.com/movieview.php?id=31442.