As far as improvements go, a new HTML scaling algorithm is in place that improves overall image quality, while tab switching has also been given a performance boost. MozTouch has been swapped out with support for W3C touch events, HTTPS pages will no longer load insecure content, and the issue with poor response when using proxies has been corrected.
In addition, a new version of Firefox for Android has been rolled out featuring some new changes that will make mobile users happy. Specifically, it has made somes changes to help keep users secure by implementing the malware detection desktop users have already enjoyed. When visting a URL that has been blacklisted, users will get a "Reported Attack Page!" warning. You can nab the app over at Google Play.