Codenamed Apollo, Windows Phone 8 will arrive on shelves as the next–generation mobile OS from Microsoft.

The platform is said to be based on the same code as the Windows 8 desktop client, which was unveiled to the world in September last year.

Microsoft is said to plan the release of both new OS versions in fall. Nothing has been officially confirmed on this, nor have details been made available on Windows Phone 8.

However, recent rumors suggest that Windows Phone 8 will be based on Windows NT, which is also at the core of Windows 8. This means shared functionality, and possible similar device capabilities.

Given the fact that Microsoft is targeting Windows 8 mainly at the tablet PC area, it does make sense for it to have the two clients resemble (smartphones and tablet PCs are getting closer to one another these days).

Windows Phone 8 is also said to arrive with support for x86 configurations, another hint at its close relation with Windows 8. Not to mention that Microsoft has recently added ARM support to the latter.

The Metro UI will be the same on both of them, but Windows Phone 8 will keep the People hub, Office apps and other hubs from Windows Phone 7. It will also offer support for applications built for this platform.

Handsets running under Apollo will feature an eMMC card inside, and might also sport microSD cards, a feature that was not present in the previous OS flavors. However, while the eMMC will support the NTFS file system, the cards will support only FAT/exFAT.

Vendors will be able to make partitions on the built-in eMMC, and some of these will be read only.

Other features expected to make it inside Windows Phone 8 would also include Near Field Communication and support for the same series of sensors as Windows Phone 7.5 Mango.

The same as with Windows Phone 7, there will be nonnative code available for devs. Instead, they will have to build apps using .NET APIs.

With Windows 8 packing a large set of mobile features and Windows Phone 8 set to include desktop-like capabilities, it becomes clearer and clearer that Microsoft is working on twin platforms this year, though nothing has been confirmed.

Windows 8 Beta is set to become official in late February, which points at a possible appearance at the Mobile World Congress in Barcelona, the same place where Microsoft is expected to make Windows Phone 8 official.