I agree that this phone would just slip out of your hand. Its not that big of a deal, just get a case. I really wish they would just make the back have a rubber coating of some sort so that I didn't need a case.
Personally, I'm probably going to be getting an Android phone next, though I've heard of many problems with the OS on different devices. I'm close to the end of my contract and am looking forward to upgrading from my 3gs.