This collection includes HD versions of Kingdom Hearts: Final Mix (which was previously Japan exclusive and includes more content, such as extra boss battles and a few more keyblades), Kingdom Hearts Re:Chain of Memories (which is the 3D PS2 remake of the GBA game, originally included with KH2 Final Mix+ in Japan and released as a standalone title in the US), and the cutscenes from Kingdom Hearts 358/2 Days. Not sure why they didn't include a fully updated version of the entire game, but I don't really care. (Drwand Needler Says)
In the ending credits of KH 1,5 they showed screens from KH 2, BBS and Re:coded in HD hinting that not only there will be a 2.5 but that its already in development. The version shown is in fact KH 2 Final Mix I know this because in the scene where it showed the opening scene for the boss fight against the Storm Rider in The Land of Dragons the storm rider had a different color scheme, in the original KH 2 it was mostly blue,in the scene seen in the credits he is mostly red, all heartless in KH 2 FM were given different color schemes (Cannal Tannel Says)
