Another JB addition is Google Now, which tailors search information based on things it learns about you over time and which HTC has made readily accessible through a longpress on the home button (just as Google intended, right?).
That tail is useful because it adds depth to the OS, in the form of a vertical row of "cards" which appear when you long-press the home button, and which grow intelligently based on what Google can glean about your life.
That 0.1 numbering gives a good indication of just how light the visible feature set might be, though -- other than an existing update to substitute the virtual menu button for a long-press of the home key, the interface changes are mostly limited to dedicated buttons for switching browser tabs and between different cameras.