Microsoft's latest salvo in the mobile computing wars, Windows Phone 7, is officially launching October 21 in Europe and Asia and November 8 here in the US. The company had simultaneous press events in New York and London today to unveil the launch hardware, including a number of devices from Dell, HTC, LG, and Samsung. Here's a quick rundown of the options coming at launch—all GSM/UMTS—as well as a bit about a CDMA/EV-DO handset coming to Sprint early next year.

Dell, which hasn't done particularly well with its Android-based Streak, will be front-and-center for Windows Phone 7 with a 4.1" QWERTY slider called the Venue Pro. Like all the launch hardware, the Venue Pro is based on a Qualcomm's 1GHz Snapdragon processor and an 800 x 480 pixel display. Where most of the hardware differs is screen size, optional QWERTY keyboard, and design. Here Dell goes with a vertical slider—with a Palm Pre-esque keyboard—instead of the more common landscape slider. The Venue Pro will be a T-mobile exclusive at launch in the US.

HTC can attribute much of its early success to Windows Mobile (then called Pocket PC), so it's no surprise the company has the most hardware ready for the Windows Phone 7 launch. The HTC HD7 is a re-packaged version of its HD2 Windows Mobile smartphone. The 4.3" touchscreen device has been popular, and already used the Snapdragon processor, so it was an easy choice for HTC to make. In the US, the HD7 is also a T-mobile exclusive, though it will be launched on a number of carriers internationally.

In North America, HTC is also launching the unusual HTC 7 Surround. This 3.8" touchscreen device has, instead of a keyboard, a slide-out "surround" speaker system. Along with its integrated kickstand, the device is aimed at users who spend a lot of time watching TV and movies with a smartphone—ostensibly someplace where a slide-out speaker wouldn't be incredibly annoying to people nearby. This device is exclusive to AT&T in the US and to Telus in Canada.

Outside the US, WP7 users will also have a choice between the HTC 7 Trophy and the HTC 7 Mozart. The Trophy gets a 3.8" display, 5MP camera with LED flash, and plastic body, while the Mozart has a 3.7" display, an 8MP camera with xenon flash, and an all-aluminum unibody.

Finally, the HTC 7 Pro is set to launch on Sprint early next year. This EV-DO device trades a little screen size for a slideout QWERTY keyboard, and it has the same 5MP camera with LED flash as the Trophy. The extra space inside the larger casing also leaves room for a slightly larger battery. The Pro continues Sprint's recent tack of getting higher-end phones as exclusives.

LG will have two handsets for the WP7 launch. Globally, the company will offer the LG Optimus 7, a 3.8" touchscreen device. In the US, AT&T is getting an exclusive version with a 3.5" screen and a QWERTY keyboard. Both models have a 5MP camera as well.

Finally, Samsung is, like LG, launching two models. Internationally, users can get the Omnia 7, featuring a 4" AMOLED display, and 5MP camera. In the US, AT&T is offering a version called the Samsung Focus. The hardware seems very similar to the Galaxy S and shares many of its specs. Like AT&T's variant, called the Captivate, the Focus is very thin and seems to have a little nicer exterior than the Omnia.

These are just the handsets that Microsoft announced today. More are expected in early 2011, including models compatible with Verizon in the US. With the current mix, however, there should be a little something for everyone looking for an alternative to iOS, Android, or Symbian.

Look for more hands-on coverage from New York and London later today.