Canon and Nikon both make great SLR's with tons of lens options, but you don't buy an SLR the same way you buy a point and shoot. You're picking a system- not a camera. The T5i will come out in a year, but lenses have a MUCH longer service life, and you'll probably spend more on them than the camera. Pick out what lenses you want, then look at the cost and performance of the Canon and Nikon equivelents.
That said, with your S95, you're already pretty familiar with the Canon control scheme so that'll reduce the learning curve a little.
I was in the same situation a few years ago and I picked Canon. A lot of it was based on their excellent 10-22 wide-angle lens, which is like 500. The nearest Nikon equivelent was something like $1200 if I recall. I also got a 70-300is- another lens i highly recommend. For walk around, I got a Sigma 17-70. It's f2.8, but there's a lot better stuff out now. I should've spent more on my walk-around lens.
Personally, I'm not crazy about touchscreen controls. The location of the buttons can change (must look at screen to control) and there is no physical feedback when you hit the button. There's a reason why all of the pro bodies have tons of dedicated physical buttons for almost every control.
All functions on the T4i are also available by button control- the touchscreen is just an alternative option, but you never have to use it.