GamersDigest have received word from Seb Downie (Producer over at Guerilla Games) that the Killzone 2 servers are currently being updated.
"We are performing a server update and will also be deploying the game update straight after that to fix a number of issues.
The patch will be going live in Europe first and the US later on today."
The maintenance is expected to last no longer than one hour.
UPDATE; The patch (1.20) has been released, it is 16MB.
UPDATE 2; List of fixes has been added.