We first heard about a possible Hitman HD Collection from Square Enix when a PlayStation 3 Trophies list was revealed back in October 2012, and now a similar Xbox 360 reveal seems to confirm that the collection is headed to Microsoft's console as well. Bear in mind that Square Enix hasn't actually confirmed any of this.
A newly updated Xbox360Achievements.org lists the full rundown of cheevos for Hitman HD Collection, with 1000 GS seemingly tied to just Hitman: Contracts and Hitman: Silent Assassin. The rumor is that the set would also include Hitman: Blood Money, which was previously released on current-gen consoles; the cheevo listing suggests that Blood Money Achievements from the previous game will carry over to the new collection.
We've reached out to Square Enix for comment and will update this post accordingly when we've got more official word.