Actually, in the video that @spike posted, at around the 5:20 mark, Dan explicitly says you can tell it to ‘cut this line and engrave everything else’. I also remember seeing them playing with the settings in another video (the one where Dan had one of his investors create a file in illustrator and send it to the Glowforge in Seattle) that clearly showed them designating one color as a cut and another as engrave. I am certain there is more than just hope.
Edit: Here is the link to the post with that video I mentioned, and in it (shot with no breaks in real time), they did in fact do the engrave and cut in a single job.