4J Studios the developer of Minecraft: Xbox 360 Edition has announced that the alternative texture packs is currently at work.

A texture pack is a group of files that is used to change the in-game textures of blocks, items, mobs and the GUI. They are zip files that have various PNG images in them and a pack.txt. The native resolution of Minecraft’s textures are 16×16 (measured pixels in block height and width). 32×32, 64×64, 128×128, 256×256 and 512×512 are referred to as ‘HD’ and requires third party modifications to run correctly.
It still remains to be seen if 4J Studios will include this in the next update (expected to be 1.2.3) or later.