Apple CEO Tim Cook unveiled the next-generation iPhone at a media event on the Apple campus today, putting an end to months of rumors and speculation about Apple’s latest smartphone. Called the iPhone 4S, it features an upgraded A5 dual-core processor, a faster wireless network and an 8MP rear camera with improved optics. The 4S retains the same size and shape of the iPhone 4, categorizing it as an evolutionary upgrade rather than a revolutionary device.

Other notable features include dual-core graphics which Apple claims is seven times faster than the previous iPhone and will really scream in games. Despite the beefed up hardware, battery life has been increased to eight hours of talk time on 3G, six hours of 3G browsing, nine hours of Wi-Fi browsing, 10 hours of video watching and 40 hours of music listening.

Apple has addressed the antenna issue that initially plagued the original iPhone 4 by including two antennas on the 4S. The phone can intelligently switch between the two for improved call quality and data transmission.

The iPhone 4S is a world phone, meaning it can run on both CDMA and GSM networks and features faster “4G-like” speeds of 14.4 Mbps down and 5.8 Mbps upload.

As rumored, the 4S has received a significant camera upgrade as well. The new shooter is now an 8MP unit that outputs at 3264x2448 resolution and features a backside illuminated CMOS sensor that lets in 73 percent more light. A hybrid IR filter provides better, more accurate colors while the five lens inside the camera provides 30 percent sharper images and will go down to f/2.4 aperture. The camera is said to snap photos 33 percent faster than the original and includes an Apple-designed image signal processor that enables face detection and 26 percent better auto white balance. On the video side, the iPhone 4S shoots 1080p HD video with real-time image stabilization and temporal noise reduction.

Apple also unveiled a new voice assistant program called Siri which is described as an “intelligent assistant that helps you get things done just by asking.” With Siri, you can ask the phone a wide array of questions in a normal conversational tone and Siri will work to deliver accurate responses to any number of questions or requests. For example, in a demo of Siri, Scott Forstall wanted to create a reminder to call his wife after leaving work. He said, “Remind me to call my wife when I leave work.” Siri asked to confirm the reminder, already knew who his wife was and set up a geofence around his work. When he leaves that perimeter, Siri will remind him to make the call.

The iPhone 4S will be available in 16GB, 32GB and 64GB capacities for $199, $299 and $399 respectively in white and black. Pre-orders start October 7 and availability in the US, Canada, Australia, the UK, France and Germany will be on October 14. The phone will be available on AT&T, Verizon Wireless and Sprint in the US. 22 more countries will get the 4S on October 28 with 70 countries having availability by the end of the year.

We also learned that iOS 5 and iCloud will be available to current iOS users on October 12 as a free update. iTunes Match will launch near the end of the month in the US.