Bug 783846 landing in Nightly means that Firefox for Android users—starting in version 39—can finally paste into contenteditable elements, which is huge news for the mobile-html5-responsive-shadow-and-or-virtual-dom-contenteditable apps crowd, developers and users alike.
"That's amazing! Can I cut text from contenteditable elements too?", you're asking yourself. The answer is um no, because we haven't fixed that yet. But if you wanna help me get that working come on over to bug 1112276 and let's party. Or write some JS and fix the bug or whatever.
Fun fact, when I told my manager I was working on this bug in my spare time he asked, "…Why?". 🎉