Good points.

Here is a (probably incomplete) list of WiMAX networks planned, being rolled out, or already rolled out: http://en.wikipedia.org/wiki/List_of...WiMAX_networks

The nice thing of WiMAX is that it, like all previous <= 4G, has roaming support which WiFi doesn't. WiFi also has a short range. Although WiMAX has a far better range, the speeds go dramatically lower if you're not near the AP. WiFi has this too, and 3G too, but with 3G there are simply a lot of APs. In one way WiMAX is the very same as 3G: the frequencies are sold to corporations who bid on these frequencies. So, with WiMAX too, you have a monopoly situation. WiMAX won't solve this problem, but it might allow corporations to compete with telcos leading to advancement in this industry. Telcos roll out WiMAX in rural areas, and not in areas where there is already connectivity. Non-telcos do roll WiMAX, to compete with telcos.

In theory, telcos could roll out WiMAX and allow users to use this with data plans and so on. But telcos want to 1) get their 3G investments back 2) limit data usage for that (either not good enough embedded device, or no tethering) 3) limit the usage of wireless 24/7 Internet connecticity so they can still earn money on their <= 3G networks. VPNs, VoIP, and tethering are often illegal by contract. The reason for this is point 2 and 3.

Unfortunately, my bottom line is, for a mobile device non 24/7 connectivity simply doesn't cut it. Say you use your NIT as a navigation system. You'd want to have accurate, recent data about e.g. traffic. You don't drive to McDonalds to use their WiFi AP to update this information. That is way too begin 90s (here it was called Greenpoint).