*edit, didnt see that the 90 minute cut scene news was already posted.....
Joystiq now has a headline CVG saying MGS4 has 90 minute cut scenes...... not containing a total of 90 minute cut scene, but an actual long length cut scene
http://www.joystiq.com/2008/05/23/br...ong-cutscenes/
this is most likely be the ending scene, as in Kojima already confirmed that this is the last of the Metal Gear Solid saga, (*although not the end of the Metal Gear franchise), so he might as well go all out with a bang for the ending....
Sons of Liberty's ending was around under 40 minutes long (totalling the amount from where Raiden was kidnap in the Arsenal Gear, not counting the interplay missions and the fight with Solidus) and Snake Eater is around 30+ minutes (same as totalling from near the certain end part of game, not including the The Boss battle)..