There are lots of rumors floating around that Canon is probably getting poised to release a "70D" as a replacement of the 60D and possibly also a 7D mk II as a replacement of the 7D.
If you compare the T3i vs. a 60D the winner is the 60D... no question. The 60D is better in nearly every way. But when Canon released the T4i, suddenly the difference was getting harder to detect. The 60D certainly has the better "body" ... dual dials, better grip, top LCD display, more functions can instantly be accessed vs. the T4i. But finally the T4i has 9 "cross-type" AF sensors (previously only available in a 60D) and the rear screen is a capacitive touch screen, and a DIGIC V processor, and a radio trigger for Canon's new speedlights, etc.
So the rumors (and these are ONLY rumors) is that they're probably poised to release a 70D because it's not too cool when a Rebel body has features which aren't available in the pro-sumer line.
The reason I stress that's a "rumor" is because the same rumor was true of the 5D II being replaced by a 5D III. I bought a Canon T1i when I WANTED a 5D. I was warned NOT to buy the 5D because... "any day now" Canon was going to release a 5D III and my money would be wasted on a 5D II. Every 6 months there was a new rumor that the 5D II would be replaced with a 5D III. I did this every 6 months for TWO YEARS. THEN.... I bought a 5D II... and about 2 months later those bastards announced the 5D III (sonofabitch!)
The point is... there's _always_ a rumor that the next better body is about to be released and you should wait. If you wait on every rumor... you'll never buy anything.