Everyone likes to play Defile, a powerful AOE spell, in their Warlock decks. With the introduction of Godfrey, we get a super-Defile and a minion in addition to it. So it serves two purposes: it clears the board, and it avoids spell breakers, such as Counterspell and Rebuke.
All Control Warlock players will want to have Lord Godfrey in their decks. It could even replace some of the staple AOEs, such as expensive Twisting Nether or DOOM!