After months of speculation, a name change, a publicity stunt burying the iPhone and Blackberry, and an uncharacteristic press event held last month (followed by an unprecedented ad campaign that's been running since then), the cat is finally out of the bag today -- Windows Phone 7 devices are now officially available in the U.S.

Three devices are available from the Microsoft online store: the HTC HD7 for T-Mobile, the HTC Surround for AT&T, and the Samsung Focus for AT&T. Any of the three devices will run you $199.99 on a qualifying two-year contract. All three are comparable in terms of specs. They vary slightly in screen size (4.3" HD7, 4.0" Focus, 3.8" Surround), and the Surround sports a slide-out Dolby speaker for enhanced audio performance. 

Engadget has a full review of the HD7, which proclaims that though it is a solid piece of good-sized hardware, but its build quality is sub-par and the screen contrast and viewing angles are poor. The Focus, on the other hand, is like the WP7 version of Galaxy S. Success or failure of these devices will depend on what users think of the new OS.

The Dell online store is offering all three devices for only $149.99, and also boasts the full-QWERTY LG Quantum for AT&T (currently out of stock) for the same price. Prices fall to as low as $99 over at the Amazon Wireless Store.

Engadget is also reporting that the Dell Venue Pro, the device that Dell employees will be trading their Blackberries in for, will be available in Microsoft retail locations.

Initial sales, though not always an indication of how a product will do (see: Android and the T-Mobile G1), will undoubtedly be closely watched by Microsoft and its competitors. Here's hoping WP7 fares better than Microsoft's last big mobile launch.