Well, the 4th Old God has been revealed:
Yogg-Saron, Hope's End
http://www.hearthpwn.com/forums/hearthstone-general/card-discussion/130267-new-legendary-card-yogg-saron-hopes-endLegendary Neutral Minion
7/5
Battlecry: Cast a random spell for each spell you've cast this game (targets chosen randomly)
Worth checking out the FAQ on this one. The gist of it is, is can play any spell from any class (even if it can fizzle like say Deadly Poison) so long as it's Standard valid if playing Standard. It also "casts" spells in a hacked way that doesn't trigger Mana Wyrm, Flame Waker, Gadgetzan, Counterspell, and cards of that nature. As for choice spells like Wrath and Discover cards, it chooses randomly.
Someone will have to do a survey of all the cards that are good and untargeted (Flamestrike, Sprint, Everyfin is Awesome, etc.) to see if this is worth playing. I just can't wait to have this autoplay Astral Communion. Like, the first Nefarian boss fight has a lot of ways for Nefarian to screw himself over with Wild Magic, like auto-playing Equality. Now you can join in on that fun!
Pretty awesome wow factor though!