Just ran into this problem today. I was hoping to make a tool for my students to take and analyze video with their iPads. With iOS 6.0, Safari does have the capability. From the Apple iOS 6.0 Release Notes:
"Support has been added for <input type="file"> tags in web forms. Users can upload existing photos and videos from their photo library or take a picture or video using the camera. Previously, this form control was always disabled."
At this point does it make sense for me to make my own plugin, or should I hold tight for an official version?