Apple unveiled a new version of its Apple TV set-top, and also made changes to its mobile operating system, as well as refreshed its iPod and iTunes products.

Speaking at the Yerba Buena Center for the Arts in San Francisco, Apple CEO and co-founder Steve Jobs spent about an hour showing off Apple's most recent innovations. Here's a look at the changes to each product segment as Jobs displayed them on Wednesday.

Apple TV ($99)
Perhaps the most dramatic revamp today was Apple TV, which Jobs has consistently declared a "hobby" for Apple. Jobs admitted that Apple had been talking to users of the company's existing set-top box for ways to improve on the product.

The company discovered that users wanted all HD content, lower prices for content, a device that was untethered from a computer, better content management and storage systems.

Apple appears to have delivered on nearly all of those points, dropping the price of the device from $269 to $99 and adding a completely cloud-based content system that revolves solely around rental content. The device features built-in Wi-Fi, an Ethernet port and HDMI out. It's about the size of a hockey puck and includes streaming content from Netflix and YouTube.

The new AirPlay feature figures heavily into the equation for the new Apple TV. AirPlay will allow users to stream everything from photos to videos to music from any iOS device to an Apple TV.

Jobs began by announcing iOS 4.1, the lastest version of the company's mobile operating system, which will be available next week. iOS 4 brings the iPhone and iPod touch a host of new features, including various bug fixes, high dynamic range photos, HD video upload over Wi-Fi and Apple's cloud-based Game Center.

Jobs also gave the audience a sneak peak at iOS 4.2, which will launch in November and centers around bringing iOS capabilities to the iPad, which is still running a version of iOS 3. iOS 4.2 will bring wireless printing and a feature called AirPlay to the all iDevices. AirPlay allows users to stream content to the latest Apple TV device, which is described below.

According to Jobs, Apple has sold more than 120 million iOS devices since launch of the first iPhone. Apple is now activating more than 230,000 iOS devices per day and has seen over 6.5 billion apps downloaded to iOS devices.

The entire line of Apple iPods got a refresh that involved mainly a complete reworking of the hardware to make each device smaller. Jobs said that Apple has sold over 275 million iPods of all stripes since its inception.

Perhaps most notably in these iPod revamps was what Apple did with the iPod touch, its most popular amongst the Touch, Nano and Shuffle. The iPod touch, which Jobs described as a no-contract iPhone, finally got a pair of cameras. The device now features a front-facing FaceTime camera, as well as a 5-megapixel camera on the back of the device that features HD video capture.

The new devices are thinner and feature Apple's A4 processor, retina display and 40 hours of battery life. The new iPod touch comes in three different version and prices, including the 16GB ($199), 32GB ($299) and 64GB ($399).

iTunes (11.7 billion downloads to date)
iTunes got a major facelift today, moving into an entirely new generation (iTunes 10) and sporting a brand new logo and integration of a completely new social network the company is calling Ping, which revolves around user-created communities built to discuss and share music.

While many were expecting a possible cloud-based streaming version of iTunes, it didn't come to fruition today. To be sure, Ping was the star of the iTunes show today. Ping, which Jobs announced is available today with the new version of iTunes, is very much like Facebook and allows users to interact with one another to share all things related to music. Users also can follow an artist to get concert information, posts and album information.