Text looks a bit different in Android 4.2
An undocumented change until now in Android 4.2 was a slight change in the way the text is displayed on your screen. Google didn’t make any groundbreaking changes but a very subtle update making the text look slightly bolder with smoother edges and improved kerning (letter spacing). This applies throughout the UI, in emails, web pages and other applications.
Look closer at the GIF and you will notice the changes.
Source: Android Central.