I have the base game and well of darkness, I am going to buy the Altar of despair soon, can I look forward to some new cool overlord cards and Heros and other stuff ? any pics would be nice

If you're surely going to buy Altar of Despair, then I don't want to spoil it for you. Be assured to find all that you expect and then some. New hereos, monster, cards of any kind (shop items, treasures, overlord cards, skills), new props and new quests, some of which might be the coolest ever, but also the hardest.

If you were asking for pictures etc. beacuse you aren't sure yet, check www.boardgamegeek.com , they host a couple of pictures for all Descent Expansions. But, as I said, if you like surprises, just go get it, and find out whats new

best wishes

Teropet

tons of pictures here. http://www.boardgamegeek.com/game/24976