> I sometimes wonder how 'humanoid' any potential intelligent alien species must be, if they exist.

TV uses humanoid aliens because they're easy to cast :)

Just look at the other intelligent life on Earth. Some birds, whales, elephants are near the top. If we hadn't nearly wiped elephants out maybe in another 10 million years they'd be making spaceships with their trunks (which have a fine manipulation ability approaching the human hand).

A little further away evolutionarily, jellyfish are remarkably intelligent and seem to even have individual personalities, and they don't have a brain.