As leaked before the company's Let's Talk iPhone press event, Apple has announced an update to its iPhone 4 dubbed the iPhone 4S. The new handset essentially looks exactly the same as its predecessor, with a Retina display and a glass back, but contains all manner of new maguffins inside.

For starters, there's the iPad 2's A5 processor running the show this time, promising to shift along at twice the speed, and there are dual-core graphics, with the potential of 7x the speed of the iPhone 4's graphics processor.

In addition, Apple is promising better battery life with the iPhone 4S; including up to 8 hours 3G talktime, 6 hours 3G browsing, 9 hours Wi-Fi browsing, 10 hours for video and 40 hours for music.

As revealed at the event, the wireless system inside has also been improved, as the new device "intelligently switches between two antennas to transmit and receive." Therefore, it promises faster download speeds: 14.4Mbps for the iPhone 4S versus 7.2 for the iPhone 4.

The rear-facing camera has been upgraded too, with an 8-megapixel sensor (3264 x 2448) and a backside illuminated CMOS, allowing in 73 per cent more light. The lens itself is also improved, with five elements, 30 per cent more sharpness, and an f/2.4 aperture. And, in software terms, there's now face recognition. In essence, it's a fully featured stills camera now.

Video too has risen from 720p in the original model to 1080p in the iPhone 4S. Plus, there's wireless AirPlay mirroring, so you can play your movies or games on a big screen.

Siri is a new feature entirely, with incredibly detailed voice commands and controls on offer, including the ability to ask the iPhone 4S the same question (such as "what's the weather in London") in a number of different ways. It's powerful stuff.

So, while there's no sign of an actual iPhone 5 (or a bigger screen), the bowels of the iPhone 4S will certainly make it a very different experience altogether.

There will be both black and white versions of the iPhone 4S from launch day, and they'll be available (in the States) for $199 for the 16GB version on a two year carrier contract, $299 for 32GB, $399 for 64GB. Former models will see a price drop, with the 16GB iPhone 4 coming in at $199 contract free, the 8GB 3GS at $49.

There's also an 8GB iPhone 4 in black and white for $99.

Release date will be 14 October for the US, UK, Canada, Australia, France, Germany and Japan (which we already knew about). Pre-orders will be open on 7 October.

All other territories will be getting it on 28 October.

UPDATE: UK prices direct from Apple have now been confirmed: from £499 for the 16GB model in black or white, £599 for the 32GB model and a whopping £699 for the 64GB version. We're waiting to see how those translate into contract prices.

The big networks in the UK have all opened up registration for the iPhone 4S, here are the pages you need: Vodafone, Orange, O2, Three, T-Mobile.

Excited about the iPhone 4S? Let us know in the comments below...