Microsoft has some serious work to do if it wants to catch Apple and Google in the lucrative mobile computing battle. While the software giant has been slow to counter the iPhone and Android, early reaction to the Windows Phone 7 Series indicates that the company at least wants to stay in this fight. Here's a roundup of thoughts on the unveiling of the new mobile operating system from some of the leading technology publications. TechFlash executive editor Todd Bishop is currently on Microsoft's Redmond campus compiling further reaction and gathering additional details, so stay tuned throughout the day for more coverage.

Joshua Topolsky of Engadget: "Forget everything you know about Windows Mobile. Seriously, throw the whole OS concept in a garbage bin or incinerator or something. Microsoft has done what would have been unthinkable for the company just a few years ago: started from scratch. At least, that's how things look (and feel) with Windows Phone 7 Series. This really is a completely new OS -- and not just Microsoft's new OS, it's a new smartphone OS, like webOS new, like iPhone OS new. You haven't used an interface like this before (well, okay, if you've used a Zune HD then you've kind of used an interface like this). Still, 7 Series goes wider and deeper than the Zune by a longshot, and it's got some pretty intense ideas about how you're supposed to be interacting with a mobile device."

Ashlee Vance of The New York Times: "Windows Phone 7 Series has a cleaner look than most of today’s phone software, with bright blue icons on a black background. One version of the initial screen has four large, square icons for Phone, People, E-Mail and Text functions that Microsoft calls Live Tiles. Underneath, a rectangular box pulls in calendar information. And below that Microsoft is highlighting its Zune music and video software and its Xbox Live gaming service. The company’s basic argument is that smartphones have all started to look the same with small square icons for various applications. Microsoft is trying to draw attention away from the application model and focus more on software that’s closer to its roots."

Matt Buchanan of Gizmodo: "The brand new, totally fresh operating system will appear in phones this year, but not until the holidays. All of the major wireless carriers and every likely hardware maker are backing it, and they'd be stupid not to. It's awesome. Further details are forthcoming, but here is what you need to know: The name—Windows Phone 7 Series—is a mouthful, and unfortunately, the epitome of Microsoft's worst naming instincts, belying the simple fact that it's the most groundbreaking phone since the iPhone. It's the phone Microsoft should've made three years ago.

Greg Kumparak of MobileCrunch: "Windows Phone is very heavy on the animations, and Microsoft is proud of it. Take the calendar, for example: when you jump from a day view to month view, it zooms gracefully from one to the other. It makes the entire interface look incredibly slick, though we’re already hearing people ask if they can be turned off (and no, they can’t.)"