Konami has confirmed that MGS4 has been pushed back to quarter 2 2008.
Quarter 2 pushes its latest release target back towards the summer; one of the slowest times for gamers with publishers typically avoiding any significant releases. It will be interesting to see if they do go with this new release target. Also curious is the reasons for the delay. They're anybody's guess, but this is undoubtedly the absolute last thing Sony wanted to see.