i've just checked that - and no, they're deffo two email addresses.
i've also nabbed dave to check (since he doesn't have GW1) - and it hasn't autolinked anything for him.
so a little concerned now, but i'll find out closer to the time.
edit - just tried my GW2 account on the ncsoft master account page, to see if i could reset the password. they can't even find the email address in records.
since it seems to be a bug of some kind, if it isn't fixed by about 6pm i'll contact customer support.
The Rangers of Ascalon