A quick look around our primary source of release dates (Amazon UK) has revealed that it has been delayed from the 16th May to the 8th June. No reason has been given for the delay of the game. Ratchet & Clank HD collection is the first 3 outings for the Duo back when they were born on the PlayStation 2 fully remastered in high definition and of course with added trophies.
We will of course keep our ears to the ground for any developments as it happens.