The dust has settled now following yesterday’s keynote speech at the Apple WWDC event, and away from all the news about the new range of Macs iOS 6 grabbed most of the headlines, and it was the new Maps feature that gained a lot of plaudits but some disappointment may be on route for owners of older devices.

The company announced a number of new iOS 6 features yesterday but according to AppleInsider when the new operating system is released in the fall, iPhone 4 owners won’t be able to use the turn-by-turn directions or Flyover in the new Maps application.

This functionality is going to be limited to the iPad 2 and new iPad, along with the iPhone 4S, which means the iPhone 4 and iPhone 3GS will both lack the ability to offer the two options even though the two devices will be compatible with iOS 6 once it is released.

The news comes from the official Apple page that previews the Maps application in iOS 6, and a footnote states “Flyover and turn-by-turn navigation will be available only on iPhone 4S and iPad 2 or later.” It also notes that “some features may not be available in all countries or all areas.”

Obviously the Siri functionality with the new Maps application will also be limited to hardware that can use Apple’s voice driven personal assistant software. For the time being until iOS 6 is released only the iPhone 4S offers Siri, but this is set to change in the fall with the addition of the new iPad and iPad 2, and any new iPhone that may be released alongside the new software.

The turn-by-turn navigation is one of the standout features of the new Maps application in iOS 6, which Apple has designed from the ground up and is going to use it in favour of Google Maps. The feature will include spoken directions, real-time traffic information, and a 3D view.

Apple’s description of the feature states that the app will provide spoken directions so drivers can keep an eye on the road, and “In addition, the screen turns into a 3D perspective view of the road ahead. Large signs and arrows superimposed over the image show you which way to go and how long it’s going to take to get there – even if your screen is locked”.

The Flyover feature will also only be available to newer devices as well, and this utilizes advanced 3D mapping data, but will only be available in cities where 3D models have been created. This news will undoubtedly be disappointing to many iOS device owners.