Installing Debian unstable

[Tomasz Muras <nexor1984@gmail.com>]

Dear Debian Installers Team,
(please CC me, I'm not on the list)

I'm installing Debian Unstable for the packaging work, using VirtualBox.
I've tried the method #3 from http://wiki.debian.org/InstallFAQ - both 
booting in expert mode and trying with priority=medium.
I don't see any way of selecting the distribution during the mirror 
selection - is such an option still there? Am I missing something 
obvious - if so, could you please hint me at how to use it?

cheers,
Tomek