you're right
pant it's not, *** off topic text removed ***
Enfoque21
I'm against the 3 steps registration anyway for many personal reasons, but there is a mod around that allow your members to register by submitting their email address then by clicking the confirmation link (in their email) they will be taken into a page to complete the registration.
I think that's close enough to what you're asking.
Now with reference to your request, it's simple & easy to do with hardly any additional codes to vB, but I don't think anyone will do it cause it has no purpose, vB registration process is fairly simple for anyone.
Further more, Good luck with your request.
Cheers.