Etna is my favorite Disgaea character and one of my favorite video game characters of all time. Her appearance in Tragedy Land in Disgaea 2 was awesome and I'm looking forward to seeing her in Disgaea 3.
As for the DLC, last time I saw the PSN it only had 4 packs Adell, Rozy, Nekomata, and the Adell/Rozy/Nekomata combo. Are you sure that's the NA PSN?
And Book Zetta is kind of lame... I'd have wanted the real Zetta. >.>