Glad to see this rumor have a reasonable take on wireless technology.
While there are, and will continue to be, growing pockets of 4G technology out there (LTE in this case...WiMax isn't a player for the iPhone, really), that's all it is...pockets. Europe, US, wherever.
I mean, come on, look at the state of 3G networks in the world. You have many areas where they are very good, mostly in Europe, Asia, and sparsely populated parts of the US. You have many areas they are mediocre (most of the US with any population to speak of - VZW or ATT). You have some areas they are non-existent (rural US, developing nations, etc).
Apple isn't the tech company that bets on niches, techie novelties, and pipe dreams. They leave that market to be built out, owned, and tested by the other players. When the technology and the build out is ready to be called ubiquitous, Apple will be there with a user experience unlike any other. Until then, despite pockets of awesome coverage, it doesn't make sense.
Europe is not covered by 4G, neither is the US. Neither geography will have water-to-water coverage that it needs for Apple to consider it a viable technology in time for iPhone 5, CDMA iPhone, or perhaps even iPhone 6.
In Europe LTE is alive and kicking, and has been for almost a year. I can get a mobile data connection with 40 Mb/s (80 Mb/s theoretical max) from my local operator. Not supporting LTE in the iPhone might seriously impact sales in Europe.