If we had waiting another 6, 12 or 24 months, whatever device was launched would be "lacking" in some way shape or form. Throw in 3G, Flash and iChat and it would just move down the list to the next thing that we all want (for me, by the way, it's a nice turn-by-turn GPS app with Bluetooth GPS receiver support).
The market is a moving target. Always will be. Fortunately, the hardware is largely upgradable through software (probably not 3G but the rest...). And then there's always the obligatory "next gen" hardware. But I'm sure that will be "lacking", too - at least in some people's eyes. In the mean time, I think the current iPhone rocks and I'm looking forward to seeing the bug fixes & enhancements as they roll out.