It's something which seems crucial to me for reaching mass adoption (in addition to scalabilty of course...).
Already on this forum there is a shitload of people losing their Bitcoins by forgetting passphrases, the private keys, the dat file etc...
Even if you forget your passphrase and loose your dat file if you are capable of saving your private keys then it is more than enough to use your coins and if you are not capable of doing that then you are not good enough to use any service .It is quite difficult to memorize the passphrases and the only solution is the save everything in a safe place.
this solution would only work for some addresses like a vanity address and the alike but wallets like blockchain would require the passphrases which very few of us
even bother to remember/memorize, its just to random. the best,less expensive and risky solution would be to have a paper wallet