The 7D is starting to show it's age with a lot of people eagerly anticipating the 7D2.
The 70D is probably a nice upgrade from a T1i. Especially in the ISO, you'll be able to get better IQ at the same ISO I'd imagine. You also get pretty much the current 7D AF system in it, so it'll be pretty decent for most sports. Buy it from a place with a 30-day money back and give it a try.