That smart guy, Carl Zimmer, has written an article on those smart molluscs, the octopus. I like that his conclusion is that we can’t really judge their intelligence, because it is different than our own.
That’s the same answer I give to questions about the existence of intelligent life in the universe. I suspect that it’s there (but rarer than most astronomers seem to think — intelligence is an extremely uncommon adaptive strategy here on Earth, as is probably likewise elsewhere), but that it will be radically different in intent and action than our own, as different as we are from a squid, or a dolphin, or an elephant, to name a few forms that have evolved large brains. Often, the question of alien intelligence is more like, “Are there people like us out there?”, and I think the answer to that one is clearly no, almost certainly not. There are too many alternative pathways.