Minecraft: Xbox 360 Edition Title Update 1.7.3 will be packed with new features, but headlining the update will be new custom skins for Steve.
As detailed by PlayXBLA, the new update will allow you to choose among the 8 Steve skins that are already in the game by default. In addition, a new Skin Pack will be released around the same time as the update, giving people who purchase the DLC more than 40 additional skins to choose from.
You won't have to blind buy the pack either. There will be a trial version of the Skin Pack, allowing you to use some of the skins for free and letting you see all of the other skins before purchasing. The Skins Pack includes both original skins and some based on other games' characters like Creeper Man, 'Splosion Man, Trials Man, Covenant Grunt, and King.
The skins don't stop here. Although, the first pack will include 40 skins, there are plans to implement even more skins in the future, although they did not say which ones.