The 5DIII will probably be this year. How experienced are you as a photographer? If you're relatively inexperienced the T2i is more than enough for now. Use it until you know all the functions like the back your hand. And develop enough skills so that the camera really becomes your limitation. You'll also find that IQ doesn't increase significantly by much as you go up the ladder. It's mostly the functions. As an example, take a look at knuckle's photos; He takes those with a 30D which is 3 generations old now. It's skill that's important, not gear. Pro photographers can get amazing photos with a polaroid camera.
There's an old photographer saying (I'm paraphrasing by memory so forgive me). Beginners want gear, amateurs want skill, pros want light.