Its not a ps2 port.The xbox 360 version wont be released at the same time as the other formats.This is taken from tombraiderchronicles website:
"Lara's character features 24 MBs of textures alone and it contains 12 times the texture memory capable on the PS2. She's comprised of 20,000 polygons - so her model is entirely re-done from the ground up on Xbox 360. The Xbox 360 version delivers 480p and 720p, widescreen and full Dolby 5.1 surround sound.
"Tomb Raider Legend on Xbox 360 boasts Normal Mapping, Specular Mapping, Diffuse Mapping, and special shaders. It's got Fernel Shader, an effect that shows off lighting effects when a light is shown behind Lara and highlights her shoulders, hips and other edges. She even has self-shadowing, meaning that when a beam of sunlight shines across her arm, her arm will cast a realtime shadow across her body. "And to top off the geek list of tech terms, the game delivers ambient occlusion: so that even when Lara is hiding in the shadows, the normal mapping still functions properly, showing off consistent highlights, shadows and skin and cloth surfaces."