Thanks to a leaked video — a video that Microsoft made for Nokia — we now have almost complete details of Windows Phone 8 (WP8). From deep Windows 8, Skype, and SkyDrive integration, through to the addition of NFC “wallet” payments and BitLocker encryption, it sounds like Windows Phone 8 will be a very exciting mobile OS indeed.

For a start, Windows Phone 8 is the Apollo update that has been bandied around for a few months. Windows Phone 7.5 will receive the Tango update in the coming months, which brings support for smaller screens, hardware keyboards, slower SoCs, and more languages — and then, alongside Windows 8 in the fall, Apollo (WP8) will launch.

Windows 8 and WP8 won’t just share a launch window, though: Windows Phone 8 is being reworked to use the same kernel as Windows 8, as opposed to the Windows CE kernel currently in use. This won’t affect application compatibility — all existing WP7 apps will work on WP8 — but it will usher in support for native code, possibly using the same Metro-style developer tools as Windows 8, and support for multi-core processors. While Microsoft says that Windows 8 apps won’t be directly compatible with Windows Phone 8, developers will be able to “reuse — by far — most of their code.”

Along with the kernel, Windows Phone manager Joe Belfiore says that security, network stacks, and multimedia support will all have a strong overlap between the two OSes. Many of the core features in Windows 8, such as app-to-app communication contracts, Metro app sandboxing, and sensor fusion will all be carried over to Windows Phone 8. Hardware-wise, WP8 will support four different resolutions (though we don’t know which ones), expandable MicroSD card storage, and presumably hardware keyboards.

Moving beyond low-level details and into user space: WP8 will bond with Windows using a standard ActiveSync-type program rather than the full Zune client; SkyDrive integration will be complete, bringing iCloud-like functionality to all of your Microsoft devices (this will work for music, too, so you won’t need to PC sync); a Skype app will enable seamless VoIP calling; and there’ll be an Xbox Companion app for Windows 8 that links up with Windows Phone.

As far as new features go, there’s DataSmart — which is very like Android 4.0’s Data Usage controls; basically, it shows you a graph of your data usage and tries to use WiFi wherever possible — and native hardware-accelerated 128-bit BitLocker full device encryption (good news for business users, and security-minded smartphone users). Browser-wise, WP8 will have a mobile version of Internet Explorer 10, along with support for Opera Mini-like proxy page compression. finally, Windows Phone 8 will support secure, contactless payments through NFC (it will have some app that’s comparable to Google Wallet).

All in all, it sounds like Windows Phone 8 will become the ideal companion for Windows 8, which is exactly what Microsoft needs if it wants to succeed in both the phone and tablet PC market. Feature-wise, WP8 looks like it will be comparable to Android 4.0 or iOS 5 — but of course, by the time it launches Google and Apple will again be one step ahead with Android 5.0 and iOS 6.

Read more at Pocketnow.com