Pixel-peep the Sony A77 at dpreview with studio-test-samples
dpreview has just posted an update saying that they have completed the studio test shots with the Sony Alpha A77 and they are available for all to pixel-peep and compare to other cameras in their studio-test-results database. The pre-filled tests there compare it to the Canon 7D, 5D Mark II and Nikonia D7000.
Don't forget, you can select RAW instead of JPEG from their drop-down menu, compare different ISO settings, and you can also go full-screen-mode when you click on "Go to full sceen mode". (practically "full screen mode" is larger than the in-text embed, but it does not fill up a 1080p screen if you maximize it to the fullest)
UPDATE: One of the features of the dpreview studio test comparison is that it creates linkable urls for each comparison. Simply create your comparison, and then cut and paste the long url from the browser address bar. Here is an example, one of the comparisons mentioned in Comment #1: JPEG ISO 800 Sony A77 vs Olympus E-PL1