Apple really stick it to Google with jaw-dropping 3D Maps and full turn-by-turn navigation in iOS 6. However, those headline features won’t be supported on hardware released prior to 2011. In other words, you’ll need at least A5-enabled iOS devices to enjoy Flyovers and turn-by-turn navigation.

This means either the latest iPhone 4S model or the second- or third-generation iPad. So, did Apple just pull a Siri, all over again?

According to Apple’s iOS 6 Preview page, turn-by-turn navigation is limited to the iPhone 4S and the second- and third-generation iPad.

“Flyover and turn-by-turn navigation will be available only on iPhone 4S and iPad 2 or later”, says the fine print. Furthermore, “some features may not be available in all countries or all areas”.

This is a bit strange knowing that iOS 6 works on both the iPhone 4 and iPhone 3GS (but not the original iPad). Another limitation worth pointing out: Maps’ Siri functionality is available only on the iPhone 4S and iPad 3, which will gain Siri compatibility later this fall when iOS 6 launches.

Likewise, the new three-dimensional view is also limited to the iPhone 4S and iPad 2 or later. Neither feature is supported on the fourth-generation iPod touch, which lacks a GPS chip.

While it’s logical that demanding and detailed 3D graphics would require the kind of graphics oomph offered by the A5 chip, it is to say the least surprising that Apple’s turn-by-turn navigation won’t be supported on the iPhone 4 as a number of third-party navigational apps run just fine on the iPhone 4 and even iPhone 3GS.

What’s Apple’s play here?

One possible reason could be the battery.

Continuous GPS tracking taxes your battery, which is not that big of an issue with the iPad’s ten-hour battery life as it is with iPhones.

On the other hand, Apple in the past limited certain features on the grounds of exclusivity.

Siri originally launched as an iPhone 4S exclusive last October and only with iOS 6 will the company take the digital secretary to the iPad 3. Conspicuously enough, Siri is not supported on the second-generation iPad.

Your guess is as good as ours so feel free to offer your explanation down in the comments.