So what can we really expect from this upgrade, spec-wise? The T2i is already very powerful for a Rebel-series camera. It uses the same (or extremely similar) sensor as the 60D and 7D, so this is unlikely to see an upgrade before the others. The auto-focus type is one of the few differentiating factors between the Rebel series and the higher-end models. It isn't inconceivable that Canon could add an articulating screen like the 60D, but again, this is one of the few differentiating features between the T2i and 60D.
While I will re-issue my desire to see a built-in GPS added to Canon's SLR lines, I don't expect to see this or any other significant upgrades for the 600D (T3i?).