I've always wondered if Mojang will make it to where you could make mods and upload them to like a community feature where you can download player made mods to your game (kind of like the Steam Workshop) Also the most popular mods like Galacticraft and Tekkit should be made available for purchase on the XBOX Live store (they should be free but if it was ever added it would be like a dollar)
This question has been asked many, many, many times. If you look around the various 360 subforums you'll find numerous threads regarding mods on 360. That being said the general consensus is no this will never happen. There are too many hurdles that 4j/mojang would need to overcome for mods to be a realistic possibility on the xbox. I guess you never know what could happen but I wouldn't get your hopes up.