buzfap01$02%014STK1456cAonImA;)7
Even at this stage my guess is that we are at a level of pretty safe entropy (provided you have not followed my formula but instead created your own).
I am not sure this would be long enough. It may be a good start, but I would say you probably need to have additional words at the end of the the above.
I don't dispute that creating brainwallets is not for everyone but I *do dispute* the idea that no-one is capable of creating a decent brainwallet.
Brainwallets just don't produce enough entropy for the seed of your private key. It's known fact that there are several groups with GPU farms creating giant rainbow tables for these purposes. It's generally considered that every passphrase that can be Googled is not secure enough for the brainwallet. There's a guy who reported that passphrase created from the entire poem written in some obscure language (Afrikaans) has been bruteforced. For instance, I've took the four words from your sentence above in random order "
capable dispute creating everyone" and it returns 0 hits on Google (until I post this, at least). This may be a good brainwallet by your criteria since if I haven't post it it would be probably safe against attackers for a very, very long time, but it has nowhere close enough entropy compared to any decent PRNG. The question is this: If it's inferior from the security standpoint then any address generated by the Bitcoin-QT wallet, why don't you let the Bitcoin-QT generate the address and after that passphrase protect the wallet with the same "capable dispute creating everyone" passphrase, making it infinitely harder for the attacker since he has to hack your machine first + hack the passphrase, instead of only hacking the passphrase?
I think this was somewhat already addressed. It was mentioned that you should not make your passphraise anything that has ever been published, in any language. If you make it truly random and something that has not been published anywhere then you should be okay. As I mentioned above, something the length of only 4 words is probably not long enough.