I don't agree with the de-emphasis of salting. Salt eradicates time-space tradeoffs. Any successful scheme is going to get used by lots of people which means a time-space tradeoff would be hugely valuable even if you have GPUs or even ASICs on your side.

Even an eyeball test shows the value of salt. Here are 4 million usernames and hashed passwords. Oh, 86000 of them have the same hash. Ok, those 86000 users have some easy to guess password, we'll break that first.