getUserMedia support for the microphone landed in FxOS v1.2. getUserMedia support for the camera just landed on trunk (v1.4) about a week ago. The final piece to land was support for permission prompts : bug 853356 in bugzilla.mozilla.org (https://bugzilla.mozilla.org/show_bug.cgi?id=853356). Prior to a week ago, you would have gotten a permission error.
Currently the camera always returns frames in landscape mode. Bug 970183 (https://bugzilla.mozilla.org/show_bug.cgi?id=970183) tracks that problem, and we're actively working to land a fix for this ASAP.