I agree, i think it should had no sharp edges on all sides, otherwise it would be uncomfortable for the user or can harm other people by accident? just a comment, in other hand the concept looks nice! ^__^
-- If people say they don't like your design, its because they don't know the design processes.
After fabrication, those angles would be just as hard - technically less than due to angle - as the the edge of the iPhone 4. If you've ever held a ZuneHD, think more along the lines of how that feels in the hand, except larger (along the size of a Samsung Focus/iPhone) It just looks really sharp due to the fact I played around with KeyShot for maybe 10 minutes before I stuck this model in.
Besides, I made a physical analogue to scale of this out of illustration board, and the angles at the bottom feel really nice in the palm, especially if you're holding the phone sideways for full keyboard texting. Some people favour a more ergonomic feel though, which is just personal preference.