[Floris]

Put pre-sales open, and be strict to requests for templates etc, explain their options, do not go into explaining how it is done.

Let them browse the hacks database, so they can see the description, but do not allow them to surf the forum. That way they can not get the info from the forum.

Users who are registered, might be able to browse the forum, some might not have a license, but know PHP or otherwise and could be of assistence (weak argument here). If they want to download anything or get support, they should be a licensed user, let them enter the legal license information as required now for downloading anything.

As a guest, I can browse through the hack database and I can request some additional info in the pre-sales section. One thread in that pre-sales section explains that the hacks are free to licences vBulletin users, and that the PS-board is only for investigating about vBulletin, not for assistence or anything for those hacks. And the guest-tour ends here. They are required to register if they need more.
When they register, they have access to the other boards, but.. if they enter their license information, they have access to the boards where they can get hacks/styles/modifications/graphics and download them.
So, unlicenced registered users can get access to boards like Help, Buttons and Graphics and/or Language Packs .. I can imagine users from vBulletin.com hearing they can find that here ..

Anyway, I vote yes ..