So I hate to say it but.. the new Gangplank sucks ass and is probably worse than before.
I mean every now and then you might be able to make a decent play late game throwing a keg and catching up to someone, or throwing 3 of them down in a team fight and doing some damage.. but other than that he sucks so bad. The barrel seems like it just doesn't fit into his play style. Maybe someone can enlighten who thinks otherwise, but I think he sucks fat hairy donkey d.
Edit: If you really wanted him to have that AoE barrel, why not make it something less predictable like a thrown barrel that covers the enemy in oil, slows them, and if you parley them ignites them for true damage?