I personally think that patent was defensive. You know, some idea they were joking about and they decided to the patent. That way, other companies can't have it and they can defend the few companies that are making lens accessories for the iPhone from patent trolls.
I don't really see it taking off. Keeping the phone and camera assembly small would be really hard while providing a decent quality. I think the multiple camera system makes more sense as the next step for phone cameras. They offer lots of the advantages of a larger sensor and different lenses in some cases without the bulk.
However, as phones get better cameras, there's no doubt in my mind that the cheap P&S market will continue to shrink. With that said, with the proliferation of these devices, so has social media and personal content delivery. It seems to me like there's more people interested in photography, video/cinematography, music production... simply because the technology is cheap enough to take the plunge and the channels exist to share your work.
There's more people into photography and videography either as a personal interest or as part of their profession. It now makes sense for bartenders, cooks, hairdressers, architects... to take pictures and share them. The market is there and is growing if anything.
Even if sensor size and ergonomics are the last thing that would separate phones from proper camera, they are huge. Top dedicated cameras can take pictures by candle light and have video quality that approaches cinema stuff, on the other hand, iPhone pictures start to get grainy as soon as it's indoors, not to mention creative freedom and usability. The general population is renewing its interest in photography that was lost in the early 2000's with P&S digicams, it's time for the MILC to grow. The vendors need to be aggressive, educate, don't cram feature but offer good value and please make phone integration seamless.
I think the MILC camera can fit into more people lives than DSLRs. You cary your phone with you everyday, get snapshots and a worthy shot every once in a while, you use it mainly as a documentation tool. You might own a small MILC camera with a few lenses that takes amazing picture and video. You can easily carry it with you when you do expect to have something to take a shot of and you can easily share it through your phone. And bonus, it can also be your workhorse when you go out on photographic adventures.