I'm pretty sure people still use them. Even better if they use something they use much heavier encryption (such as WarpWallet).
The idea of simply remembering your money is appealing to me (but I don't dare risk it for a large amount).
What I don't understand is why don't they use the hash function millions of times to make their brain wallet even more secure? We all know that just hashing a subjectively difficult passphrase isn't as much secure as it is to generate an entropy randomly. There wouldn't be such thread if brain wallet users hashed more than once, because, apparently, some passphrases aren't as strong as they thought.