Better? Yes, due to incremental upgrades Canon has made over the years. Appreciably better on a smaller print? Probably not.
In certain conditions, some of the capabilities of the T2i (high ISO performance, faster drive mode, better metering, etc.) would likely allow you to capture images that you might not get with the XTi. There are other bells and whistles that are useful and make newer cameras easier/more fun to shoot with, as well.
However, for the majority of shooting conditions, the XTi is still more than capable of delivering great images, especially for a smaller print.