From page 98 of the UnOfficial Ask the Dev team non-Killzone related questions thread, Seb Downie, one of the few sources of real info on Killzone today posted a brief reply in response to when the PS3 Killzone site will be online.
"We are fixing the last couple of legal issues and then it will go live."
Seb Downie - Lead Tester - Guerrilla Games
Sorry folks this was a bit misleading.
Apparently Downie has clarified his previous statement:
"At this stage there will not be any PS3 stuff. Yet. But there is going to be a lot of cool stuff on there."
The keyword here is yet..