The iPhone 4 era has officially dragged into overtime today, and the iPhone 5 waiting game with it. A year ago yesterday, Apple launched the fourth generation iPhone. And according to Apple’s traditional annual gaps between product generations, the iPhone 5 should have theoretically been here yesterday. That makes today the first day of overtime, an extra period which could stretch any amount of time at all thanks to Apple’s silence – but more likely pegged to a stretch of one to three months. And the overtime play increasingly appears to be centred around iOS 5, which Apple has already shown off to developers and the public, but whose latest “beta 2″ has revealed isn’t ready yet. In other words, Apple hasn’t yet begun building the iPhone 5 because its operating system isn’t ready yet anyway. So what does this new delayed-gratification era for the iPhone 5 mean? Here are a few areas in which the iPhone 5 arrival overtime stretch could impact the iPhone 5 era itself.

Launch inventory: The iPhone 4 and iPad 2 both suffered from not enough inventory to go around at launch, followed by a shortage of over a month in which delays ruled the era. The iPhone 5 launch is happening so much later than it could have, so that suggests that Apple will have plenty of time to build up a massive initial iPhone 5 inventory lead – assuming Apple has learned its lesson from the last two launches.

4G LTE usefulness: If Apple is adding 4G LTE to the iPhone 5, a higher percentage of Verizon and AT&T customers will be able to put the feature to use from day one, thanks to the fact that the iPhone 5 is coming later – offering some consolation for the wait.

iOS 5 readiness: Last year, iOS 4 just didn’t seem to be ready for the iPhone 4 launch. Features like AirPlay and AirPrint were delayed or scaled back. iOS 4.1 and 4.2 were the more meaningful releases, and they came later. With Apple taking its time on iOS 5 and holding up the entire iPhone 5 launch until the latest iOS is ready to go with it, users can cross their fingers that iOS 5 will be more of a complete, finished product from day one.

Fall forward: The iPhone has always previously launched in the summer, leaving it to be thought of as somewhat of an ageing product (at least by Apple standards) by the time the holiday shopping season arrives. But with a perhaps September 2011 launch, the iPhone 5 will be thought of as still being new by Christmas time. That could make the iPhone 5 more of a holiday-gift type of product, particularly if Apple figures out how to allow people to give them as under-tree gifts without having to invoke a gift card.

Pent up or drawn down: One the one hand, the dragged-out iPhone 5 launch means that more current iPhone users (and for that matter, more current Droid users) will have seen their upgrade-eligibility cycle arrive. People who would have had to pay four hundred bucks for the iPhone 5 in June could instead end up only having to pay two hundred for it when it launches in the fall. After all, upgrade eligibility unpredictably arrives in anywhere from twelve to eighteen to twenty month cycles – and this delay buys those users more time. But on the other hand, the longer the iPhone 5 takes to arrive, the more likely the interstitial models like the Verizon iPhone 4 and the white iPhone 4 become options in the minds of those tired of waiting. And if anyone plunks down on any iPhone 4 variation right now, they’ll be priced out of buying an iPhone 5 any time this year. So when it comes to initial iPhone 5 sales, the ratio of gains to losses brought on by the late arrival remains to be seen. Here’s to the highly anticipated iPhone 5.