At least IGN predicts so...
In the latest PS2 IGN feature article, Jeremy Dunham predicts that one of the major things to happen this year is the unfortunate delay of Metal Gear Solid 4: Guns of the Patriots for 2008.
"Metal Gear Solid 4 Pushed to 2008
It's the news that nobody wants to hear, but after a hell of a lot of development time already, Hideo Kojima will delay his highly-anticipated final chapter of the Solid Snake story so that it can receive "more fine tuning" -- particularly in the online multiplayer department. I expect to see it pushed back to a Q1 or Q2 '08 release in Japan, while the American and European debuts are held back until quarter number 4.
Sadly, nobody at Kojima Productions or Konami Digital Entertainment will break the news to anyone until late in the summer or beyond."
We all hope this is not true. We've been told that the online part from MGS4 might be released as a separate game after all. The same we discussed in our latest episode of the PTT Podcast.