The Killzone 2 Demo is up on the UK PSN store; it's 1207MB.
It will be up officially for North America and Europe on February 26. What is Sony thinking??? They should get this game available to as many people as possible, right now. I don't think should have just limited its release to Europe only. They need a lot of buzz for their game, and it isn't helping that they had to have some weird release schedule for their demo like this.
From what I've read, there doesn't seem to be anything stopping anyone from making a European PSN account to download the demo....hmm....