The Last Guardian will be released December 6, 2016 exclusively for PS4.
This implies that nothing exists beneath helmets in the first place, which raises a new question of whether The Last Guardian and Ico exist in the same universe.
Similarly to Ico, it appears that The Last Guardian will feature enemies, a combat system, and weapons.
Though it has experienced a multitude of delays since its announcement in 2009, The Last Guardian is slated for release on December 6, 2016 as a PS4 exclusive.