(Credit: Aloysius Low/CNET)

Samsung today announced the highly-anticipated Samsung Galaxy S III at a major press event in London. The quad-core, high-definition, Ice Cream Sandwich smartphone will be Samsung's most advanced Android handset yet, and will challenge the iPhone and the well-received HTC One X Android smartphone in the coming months.

The Galaxy S III will sell in Europe in May, followed by other regions worldwide. An LTE version of the phone is expected to come to the U.S. in summer, a year after the Samsung Galaxy Nexus launched on Verizon.

Many of the phone's rumored features have, in fact, come to pass. The Galaxy S III features Samsung's quad-core Exynos processor, a 4.8-inch HD AMOLED screen, and an 8-megapixel camera. Samsung has also customized a variety of features, including a custom interface it calls TouchWiz, and variations on Google's Ice Cream Sandwich camera apps and voice commands.

Samsung also added onto Android 4.0's NFC-sharing feature, Android Beam (video). Called S Beam on the Galaxy S III, this enhanced version also transfers files in addition to maps, apps, and browser URLs.

The Galaxy S III will sell in white or blue.

Samsung's Galaxy S III succeeds the Samsung Galaxy II series, which was the most popular handset in Samsung's history, selling 20 million units in 10 months. The Galaxy S II's global success was also instrumental in Samsung's record quarterly profit.

Read CNET's hands-on take of the Samsung Galaxy S III for even more specs, features, and thought on how it stacks up against the HTC One X.

Correction, 11:30 a.m. PT: We were originally told a December release for the U.S. version of Samsung's Galaxy S III with LTE, but we're now hearing summer.