Microsoft has announced that Windows Phone 7.5 users will be getting an update to Windows Phone 7.8 later in the year, but what features will you get when you upgrade from Windows Phone 7.5?

Windows Phone 8 Start screen

While Windows Phone 7.5 users won't be getting many of the new features coming to Windows Phone 8 because of hardware restrictions, the OS update will bring the new Start screen allowing you to fill the entire screen with tiles of varying sizes.

That means the gutter down the right-hand side of the screen is now gone, as too is the helpful arrow that pushes you to the App list.

It will also mean, however, that you can get a lot more "At a glance" information on the Start screen at one time.

New live tile sizes

Windows Phone 7.8 update will add support for two new tile sizes to the Start screen. There will also be more customisation, with new theme colours beyond the dozen or so colours available in Windows Phone 7.5.

The new small tiles take up a quarter of the space of a Windows Phone 7 tile, but can still display information - making them about the same size as the iPhone app icons but interactive, as is already the case with the Start tiles.

A second new tile added to the Start screen is a large tile that takes up the full width of the screen. Previously Microsoft and phone manufacturers have used this size tile for apps such as the Pictures tile or Calendar, but now any application will be able to be stretched to the new size. It will be up to the developer to determine whether any additional information will be available.

Windows Phone 7.8 update

Microsoft has confirmed that the update to Windows Phone 7.8 won't be operator specific and will be pushed out by Microsoft itself directly to the WP7 device, either via Wi-Fi or via the Zune or Windows Phone Connector for Mac software.

Windows Phone 7.8 apps

Microsoft has said that all Windows Phone 7.5 apps will work with Windows Phone 7.8.

Developers will still be encouraged to develop apps for Windows Phone 7.8 as they will automatically work on Windows Phone 8.

However, apps designed to take advantage of specific Windows Phone 8 features won't be backwards compatible.

What's new in Windows Phone 8?