The drop-down dialog is also wider to provide a better overview of matching logins, including username and time of last use. As you start typing out a username or other keyword, the selection autosorts to narrow your choices.
It's a small tweak, but one that aims to make the autofill menu more usable for those with dozens of matching logins for a given site.
The updates have also been pushed to Safari, and will be pushed to Firefox and Internet Explorer in the near future.
Tell us what you think in the comments below!