Zen, I agree with you completely here - not everybody will want to go through extreme measures to log into a game. But some people wouldn't want it any other way, which is why I suggest an optional additional security measure that could be enabled or disabled by each player. Take EU's Gold Card for example: if you purchase it (or have one sent to you based on your deposit total) and enable it, you will be required to use it to log into your account, but if you don't have one or don't enable it you can still log into your account without it.
And the point about email taking a while is probably the best reason not to use it. Many times an email comes through, but more often than you might expect there are long delays between an email being sent and when it is received. The same is true for SMS messages, unfortunately. These facts being the case, I can see why the Secret Question has been the primary way to increase security in other MMOs. The questions are already on the server, all we have to do is provide the answers.
So the best way to provide a combination of extra security and account-owner customization is to require at least one Secret Question, but allow several more. And the best way to answer those questions is with answers that do not make sense for the question to make the SQs even more effective.