There's no technical reason for Mt. Gox to lock the second profile.  If they left it open then you could use it for whatever you wanted, static password, Challenge-Response, a Yubico OTP, whatever but nope, they decided to lock it in to Mt. Gox only.  I suppose an argument could be made that it makes it so that if you hold the button down past the first profile's time it'll activate the second and still get you in but that's about it.  Hopefully they'll just give out the key soon so people can take advantage of the other profile, especially since they're paying a premium for a pre-configured one.  (Ya I know, labor to configure/ship etc them)