Last year, Microsoft pushed reset on its smartphone strategy, jettisoning the old-fashioned Windows Mobile platform for the more modern and innovative Windows Phone. This year, Microsoft is back, with a soft reset of sorts, offering a more fully-fleshed-out version of the software, and—starting this week—a new slate of improved hardware that can take advantage of the new features.

For US-based consumers, Windows Phone Take 2 starts now, with a new lineup of handsets based on Windows Phone 7.5, the curiously named second-generation version of Microsoft's new smartphone software. The lineup is a bit smaller than it was a year ago but far more competitive from a features and specs perspective. Today, you can choose between four different phones from two different hardware makers on two wireless carriers only. But Microsoft tells me that the Windows Phone 7.5 lineup is going to grow dramatically in the days ahead.

"Windows Phone will help change the way people look at smartphones," said Microsoft President Andy Lees, who oversees the Windows Phone Division at the software giant. "Other phones have you wade through a sea of apps, while we bubble up all the things that are important, centered around the people that matter to you most."

At a retail availability launch event in New York yesterday, Lees and fellow executives from the Windows Phone Division provided some hands-on time and background information about the company's second-generation offerings. Today, this consists of two phones each from HTC and Samsung, which are available on AT&T Wireless and T-Mobile. These include:

HTC Radar (T-Mobile).  This elegantly made handset is "crafted from a single piece of polished aluminum," according to its maker, and is available in white and gray versions. It features a 3.8" screen and costs $100 with a two-year contract. 

HTC Titan (AT&T). The biggest of the second-generation Windows Phone handsets with a 4.7" screen, the HTC Titan isn't actually available for purchase today but is instead "coming soon"—I couldn't get anyone to commit to a more concrete timeline—and will feature a 1.5GHz processor, a very thin 9.9mm form factor, and an 8-megapixel camera with dual flash. The Titan's camera is clearly the best of the second-generation handsets by a wide margin and appears to be on par with the camera offered in the Apple iPhone 4S.

Samsung Focus Flash (AT&T). This very small and inexpensive new Windows Phone includes a 3.7" screen, a 1.4GHz processor, an 8-megapixel camera, and a thin 8.55mm form factor. It looks a bit like previous-generation "candy bar" phones thanks to its size and shape and will appeal to consumers looking for a smaller device. And it costs just $50. I have a few screenshots of the Samsung Focus Flash on the SuperSite and will be reviewing this device soon.

Samsung Focus S (AT&T). The successor to the most popular first-generation Windows Phone handset is perhaps the nicest all-around second-generation device, with a large 4.3" Super AMOLED Plus display, 1.4GHz processor, 8-megapixel camera, and an incredibly thin 8.5mm form factor. The Focus S costs $200, and I'll be reviewing it soon. I have a few screenshots of this device available on the SuperSite as well.

Microsoft claims that each of the devices is capable of "4G" speeds, but—in the case of AT&T at least—that's a bit of a stretch, as AT&T has yet to roll out a true 4G wireless network, relying instead on the 3G-based High Speed Downlink Packet Access (HSDPA) improvements.

There are other questions. Although the software giant didn't discuss Sprint or Verizon Wireless explicitly, I was told several times that Verizon was on board and would have an announcement of its own in the coming days. And Nokia wasn't available at the launch event: My sources tell me that Nokia will announce and ship its first US-based Windows Phone handsets at CES in January, however. 

And though Microsoft has made enormous headway with its Windows Phone apps library—which now features more than 35,000 titles, according to the company—some key apps are still unavailable. Microsoft announced that the Spotify digital music service was launching on Windows Phone this week, but key apps such as Audible, Lync, and Skype are still missing in action, and there was no word when these apps would ship.

Overall, Windows Phone 7.5 is a big improvement over its predecessor—see my review for more information—and combined with modern hardware it provides a very compelling alternative to the increasingly tired and copycat offerings from Apple and Google. But there are still questions concerning the platform and whether wireless carriers will ever be serious about selling these devices. I heard from multiple users who visited AT&T retail locations on Sunday and Monday to inquire about the new devices, and every one of them was questioned by AT&T employees about their choice and directed to Apple and Android handsets.

I'll have a lot more to say about Windows Phone 7.5 and these new handsets in the days ahead, of course. Stay tuned to the SuperSite for Windows for ongoing coverage.