"Deathrattle: Draw a card" is a little weaker than "Battlecry: Draw a card", so it can stand to have one more stat point than Gnomish Inventor. It's still decent though, and I'd play the hell out of it in Arena.
Im trying to understand how someone thought it would be a good idea to make this card, but the real genius is the guy who thought that opening the announcement with this card was a good idea. Facepalm.
I honestly dont see how people are hating on this design. Cult Master requires you to have a boardstate before you drop him where as this guy is the inverse of cult master in that he requires no board state to drop. If you do have board control then dropping him in means you can use him to trade up potentially. Personally I think its a good design in that its got enough power to be relivant in trading and does not die to hero powers. When you look at 3 drops and 2 drops most of the ones that see play are minions with 3 power and 2-4 toughness so this falls in nice where he trades with most minions that cost less than him still but he can also trade up with his high power.
I think he is being sold short. He might not be the next format defining card but I think he is better than the comments I am seeing.