You know, that's a great question and one I've pondered a bunch. The whole process is a bit more complex fundamentally but I bet it gets pretty close. I can see a day where you just snap a canister onto a printer (your filament), take out one of your pretreated substrates (maybe not glass by then...but the same as loading a piece of paper), place that on the bed, and send your model over. Come back in a bit and pull out your part. I don't see why not.

What I do see is that the user is going to have to be a tiny bit more savvy than your standard Epson printer user. If you get a jam or some other issue you'll need to do some fast diagnosing to get things going again. Maybe print heads will become disposable and if you get a jam, you just pull it out and put a new one in. Who knows for sure. One thing we do know is that the more units that are sold (...the more ubiquitous the printers become), the cheaper each component gets. So there is reason to suspect that many of the components, filament, print substrate, heads, stepper motors, etc., could all be plug-and-play and disposable should one cause an issue. The printer could even be smart enough to say "head jammed...please replace and start new print." Or, "stepper motor failure, please remove and replace with new module and restart print." I expect we'll see Canon, HP and Epson fight each other to be the first to have a "click-and-print" 3d printer.