So here are my two cents on MCX360: Slow. Minecraft is a game designed for the PC, so using a controller slows down movement and user interface by introducing analog sticks versus a mouse and keyboard. To compensate for this, I think that the Xbox chat pad (pictures follow) be compatible with the game.
Not using the pad instead of a controller, but utilizing the hotkeys 1-9 to speed up hotbar movement. Spamming L and R bumper gets redundant and annoying. So to fix this, why not let us have the same hotkeys that PC players have? It only makes sense.
This is a perfect solution because Microsoft prevents you from hooking up a keyboard and mouse to your Xbox, so go around the system and make it so we can use the chat pad for HOTKEYS! All I am asking for are 9 buttons!