XBOX 360 Save Format Update: Copyin some info from my thread here.
http://forums.xbox-scene.com/index.php?act...t=462595&st=90#Since it basically relates to this area.
XBOX 360 Gamesaves (not legacy xbox1 saves) are hardcoded to each profile they reside in. Therefore, we won't see any sharing of gamesaves (RE: xbox-saves.com) this generation. Unless one would want to download an entirely new profile to say play the last level real quick or somethin. Nothing two helpful.
Each profile is given it's own 'ProfileID' which it uses to store its gamesaves and uniquely save them.
For example here is the layout of a gamesave with just Call of Duty 2.
CODE
/Content
/E0000ECA5A5364A4 <- Profile-ID
/FFFE07D1 <- Dash Version/TitleID
/00010000
/E0000ECA5A5364A4 <- Profile Data File
/415607D1 <- Call of Duty 2 TitleID
/00000001
/savegame.svg <- Call of Duty 2 Save
Each profile will contain the Profile Data File as well as a folder for each game's titleid and the contained saves.
Each savefile will contain the 'ProfileID' at offset 0x371 in the file. Thus, giving it some unique data and is then signed with the 2048 bit key. That way, this gamesave can be used ONLY with the profile data of the same ProfileID. Profile Data File's are signed as well, leave out any room for adjustments.
Arcade Content, Movies, Music, and Themes are a bit different. They are transferrable between profiles and between consoles.
Structure Example:
CODE
/Content
/0000000000000000 <- Blank instead of a 'ProfileID'
/584107D1 <- TitleID of Hexic
/000D0000
/584107D100000001 <- Hexic Package
/FFFE07D1 <- Dash Version/TitleID
/00020000 <- GamerPicture Collection
/FFFE07D11000.GamerPicture <- PIRS Archive Containing 64x64 PNG
/FFFE07D11001.GamerPicture
/00030000 <- Theme Collection
/easportstheme <- PIRS Archive of Theme - Wallpapers+Guide Image
/guntheme
/halo2theme
Based on my findings. The content appears not to be signed unique to each console. Moving from one console to another shouldn't be a problem as long as you place it in the correct directories.