Heh, that new camera != great photos? I'd hope we all know that already. A good camera definitely helps give you the tools to be capable of taking good photos though. It is no replacement or even close approximation for a good eye.
Whether you're a fan or not, Ken Rockwell puts it nicely: A good camera's job is to get out of the way (that's from memory, not an exact quote). Higher-end models like the 70D (not to meniton full frame options of course) make it easier to use the tools available, namely without going into menus and fiddling around. More physical controls = easier settings changes, hence why I've wanted a 70D, among many other reasons (lower high ISO noise is a big one too, burst speed, there are too many upgrades over my T3 to name here).
Anyway, can I take decent photos with my T3? Absolutely. Well, I hope so, heh. The 70D will just make it easier to get the shot. It will 'get out of the way'.