I have not yet had the opportunity to deepen the subject, but I made some videos and I took some pictures. What I have seen is more than promising. Piqué exceptional abbérations almost nonexistent, noise almost missing autofocus. AWESOME. We would even regret not having bought "that" alpha 57 and not 77. Store your 18-55 kit and start doing photography with a capital P and video with a big V. Why I do not give 5 stars? Because I have not had the opportunity to do a lot of takes.
Alpha 58 arriving in shops, I think to resell the A57 and aims to accentuate the definition pictures by purchasing a 58 alpha or alpha 77.