Also just a quick note: when looking at the comparisons, or reviews online, be careful to ALWAYS read the full review, and all the points, look at the actual stats, etc. I only say this because some of the quick summary bullet points on pages like that site above can be misleading. For example, they list 'reasons to buy' for each camera, which might cause one to think that if a reason is listed, it must be something better than the other camera...but it's not. With the A57, they list the color depth and dynamic range as reasons to buy, but they hadn't tested the T4's color depth or dynamic range so there's no way to know if it's better or worse. For the T4, they list in-camera HDR, phase-detection video autofocus, and continuous movie focus as reasons to buy, but the A57 also shares all of those same features. (Even though I shoot with one of those brands, I honestly feel they're all very close in performance and overall image quality, so it tends to be features and feel that help find the best camera.
It's important to always read through a lot of reviews, comparisons, tech data, look at samples, get user opinions...but in the end, it's still going to be down to what you decide is best for you.