The studio "haven't come to a conclusion" yet but it could happen. God of War 3 had a demo in the God of War Collection. Keep tradition alive Team Ico!
"We’re considering it, but we haven’t come to a conclusion," said Fumito Ueda, asked if they would squeeze a demo out for The Last Guardian to be included in the HD remake of ICO and Shadow of the Colossus.
The Last Guardian releases exclusively for PS3 this holiday. The ICO and Shadow of the Colossus Collection releases on PS3 this spring.