I love this concept. I already carry one of those cheap ebay attachable lenses for my Lumia. It fits perfectly in my cargo pants or even jeans. I don't use it much but when I'm at a sporting event or a show I attach it and get instant Zoom.
Of course the quality is not very good. If I could do the same thing with the QX and get REAL point and shoot quality, I'm sold. I just have to see how big the actual units are in real life. If it won't fit in a pocket, then I can't see the appeal. At that point, Yes, you may as well carry a separate camera.
Devices owned (Yes, I Have a problem)
Iphone 3GS, and 4, Archos G9, Acer Iconia Tab, Asus Transformer, Dell Streak 5 and 7, Galaxy Captivate, Tab 7, and 8.9 Galaxy S2, Captivate Glide, Note 1, and 2, Mega, HTC Amaze, LG Optimus 4x, Sony Tablet S, Tablet P, Xperia Play, ION, X10, X10 Mini and Xperia Z, Pantech Flex, Pantech Sky Vega S5, Toshiba Thrive, Pantech Element, Nokia 808 Pureview, Motorola Backflip, Xoom, Razr, Razr HD, Huawei Ascend Mate, Nokia Lumia 920,LG Optimus VU, Pro, HTC One.