You could create an NPAPI plugin. That would be annoying for you and users. You could use flash. Or you could wait for the HTML5 Device Capture API (or whatever it becomes... http://www.w3.org/TR/html-media-capture/). It doesn't look like it is happening anytime soon though.
we struggled with the same desire to _not_ use flash, but were ultimately forced to. That said, you can still stream back the recorded video to iOS devices or other html5 clients using wowza