AT&T launching the Samsung Galaxy S II Oct. 2 for $199

The fastest selling Samsung smartphone, the Galaxy S II, arrives on AT&T’s(s t) network October 2 for $199 after contract. The carrier shared the release information Wednesday on its Facebook page, saying the phone will be available both on-line and in retail stores on the launch date. The high-end handset has been available in countries outside the U.S. since May and sold 5 million units in the first 85 days after launching.

Timing of the Galaxy S II on AT&T should prove interesting as the smartphone is arguably the best suited Google Android (s goog) handset to compete directly against Apple’s iPhone(s aapl), which is still a top seller on AT&T’s network.

The October 2 launch date for Samsung’s phone appears to be prior to an expected new iPhone. Apple is reportedly holding a press event on October 4, where it’s likely to introduce the next iPhone although the handset may not be available immediately. That would mean the Galaxy S II could enjoy several weeks of sales without competition from the newest iPhone model. Knowing that an updated Apple handset is due soon, however, consumers may hold off on the Samsung device.

To recap the functions and features of the Galaxy S II, the handset uses a fast dual-core processor and large, 4.3-inch Super AMOLED Plus touchscreen. The thin handset also includes an 8 megapixel rear camera capable of capturing 1080p video which can be piped to a high-definition television set. A 2 megapixel front-facing camera can be used for video chat. And in terms of usability and performance, our own Darrell Etherington said this in his review: “This is the device that comes closest to creating a mobile experience as smooth as Apple’s.”

Of course, Darrell compared the Galaxy S II experience to last year’s iPhone 4. I’m curious to see consumers make the same comparison with Apple’s newest phone, which should rival the Galaxy S II in terms of hardware features. I’ve already suggested that a late U.S. launch of Samsung’s hottest phone could limit sales; we’ll find out next month.