I see this is an old thread, but in case anyone is still looking for something like this (as was I), I came across a product called textbox.io tonight from a company called Ephox (looks like they bought out TinyMCE as well).
Anyway, this is the first, if not only, javascript/HTML5 editor I've found that successfully pastes images from word using a proprietary plugin they call PowerPaste. Upon the initial paste, it prompts to hit paste again in order to import the images. Worked like a charm - only problem I had was that it's hellishly expensive for a startup like the one I'm involved in at $500+ per month (±R6,650+ per month in ZAR), which prices it out of our options unfortunately :(