I personally use iOS, Android and Windows Phone mobile devices and would definitely put my vote in favor or "Windows Phone 7.5" for common non-tech, day-to-day, cellphone usage. Microsoft kept the "new release" announcement momentum going after unveiling the Microsoft Surface tablet computer, with revelation of successor to its popular Windows Phone 7 - the all new, company's next generation mobile operating system "Windows Phone 8".

The announcement revealed only the new core platform capabilities and no end-user features were disclosed apart from the fact that Windows Phone 8 comes with a newer Start Screen allowing users to re-size the tiles and customize their colors. To start the new mobile OS will feature support for multi-core processors having upto 64 cores, support for two new screen resolutions—1280x768 and 1280x720, support for removable MicroSD cards, NFC wireless sharing, Internet Explorer 10, Digital Wallet, Better maps and directions with integrated Nokia Maps and more. Details and videos posted after the jump

Sadly, the announcement also comes with some bad news for existing Windows Phone device owners. Microsoft has now confirmed existing users won't be able to upgrade to Windows Phone 8 citing the fact that the new core-features are not tailored to work with legacy device hardware. However, another update "Windows Phone 7.8" will allow existing users to upgrade and enjoy the new Start Screen with ability to re-size tiles and color customizations.

Windows Phone 8, new official details :

• Multi-core processor support: As reviewers have noted, Windows Phone runs buttery smooth on phones with a single processor. But piggybacking on the Windows core provides support for multiple cores—so we’re ready for whatever hardware makers dream up.
• Bigger, sharper screens: Windows Phone 8 supports two new screen resolutions—1280x768 and 1280x720, opening the door to amazing new handsets with high-definition 720p displays.
• More flexible storage: Windows Phone 8 supports removable MicroSD cards, so you can stuff your phone with extra photos, music, and whatever else is important to you, and then easily move it all onto your PC.
• NFC wireless sharing: If you haven’t heard the term “NFC” yet, I’m betting you soon will. This emerging wireless technology lets phones share things over short distances. In Windows Phone 8, it helps make sharing photos, Office docs, and contact info easier—just tap your phone another NFC-equipped device. How cool is that?
• Internet Explorer 10: The next version of Windows Phone comes with the same web browsing engine that’s headed for Window 8 PCs and tablets. IE10 is faster and more secure, with advanced anti-phishing features like SmartScreen Filter to block dangerous websites and malware.
• Wallet: Windows Phone 8’s new digital Wallet feature does two great things. It can keep debit and credit cards, coupons, boarding passes, and other important info right at your fingertips. And when paired with a secure SIM from your carrier, you can also pay for things with a tap of your phone at compatible checkout counters.
• Better maps and directions: Windows Phone 8 builds in Nokia mapping as part of the platform. Our partnership will provide more detailed maps and turn-by-turn directions in many countries, plus the ability to store maps offline on your phone so you can work with maps without a data connection.
• Cooler apps and games: Basing Windows Phone 8 on the Windows core will unleash a new wave of amazing apps and especially games, for reasons I’ll touch on in a moment.
• Native code support: Windows Phone 8 has full C and C++ support, making it easier to write apps for multiple platforms more quickly. It also means Windows Phone 8 supports popular gaming middleware such as Havok Vision Engine, Autodesk Scaleform, Audiokinetic Wwise, and Firelight FMOD, as well as native DirectX-based game development.
• In-app payments: In Windows Phone 8 we make it possible for app makers to sell virtual and digital goods within their apps.
• Integrated Internet calling: In Windows Phone 8, developers can create VoIP apps that plug into our existing calling feature so Internet calls can be answered like traditional phone calls, using the same calling interface.
• Multitasking enhancements. Windows Phone 8 now allows location-based apps like exercise trackers or navigation aids to run in the background, so they keep working even when you’re doing other things on your phone.
• Device encryption: To help keep everything from documents to passwords safe, Windows Phone 8 includes built-in technology to encrypt the entire device, including the operating system and data files.
• Better security: Windows Phone 8 supports the United Extensible Firmware Interface (UEFI) secure boot protocol and features improved app “sandboxing,” so the phone is better protected from malware with multiple layers of security.
• Remote management: With Windows Phone 8, IT departments can manage apps and phones remotely, with tools similar to ones they now employ for Windows PCs.
• Company Hub and apps: Companies can create their own Windows Phone 8 Hub for custom employee apps and other critical business info.