Looks like Killzone 3's joined the queue of games getting a multiplayer Beta.
Sony's launched a website for the taster, although you're greeted with a sign in screen at the moment, and can't proceed any further.
This does seem to be a pointer towards a public Bbeta announcement in Cologne next week. We hope so anyway.
It's worth pointing out, Killzone 2 also had an NDA'ed Beta trial in the US and in Europe via SCEE's Beta Trial Members scheme in late 2008, so it may be something like this as well.
You can check out the site for yourself here.
Killzone 3 launches in February 2011 for PS3.