Open wireless network?
Not hardly! Skype for iPhones is good because it means people can make calls at their home any time to other Skype users, without cost, and without sitting at a computer. Skype becomes more powerful with less incentive to be "open". You can't just make your own Skype compatible application.
The next step is to have "phones" with WiFi, that can install applications without restriction (this is the heart of open), including VoIP. Basically computers in a cell phone package, that don't have a cell phone plan. I think the Android platform is closer to this than the iPhone, but Microsoft is even closer, because they have software compatibility. MS just can't seem to do phones right.
It'd be bad business for carriers to sell something that doesn't require them, we shouldn't expect it to come from them. Probably Dell, a netbook maker, or former PDA maker.
The hardest step is network neutral universal wireless internet coverage. The only way to get that is to have so much demand for it, that the market can't ignore the demand. Google seems to be the only company with the will to make it happen, and they don't have enough cash to do whatever they want. Also, we need the current internet to be network neutral if we want the future internet to be network neutral.