A reputable Windows Phone site in Russia has leaked out a comparison chart that details the differences in features between Windows Phone 7.8 and Windows Phone 8. Not only that, it throws in a spanking new feature for Windows Phone 8 that not many people have heard of before. Most of the features are already what we have expected based on Microsoft’s announcement, and there are no real surprises at all, but it is perfectly all right to see just what happens in between now and then. WP7Forum has been rather reliable to date, so this kind of information is worth trusting even though it is leaked. something you can trust.
Many people expect Windows Phone 7.8 to come with the new Start screen, and they will not be disappointed at all, with the new addition of Tile sizes. Majority of the other features will not be making the cut though. You will be able to find Skype, RCS-e, and DataSmart in Windows Phone 7.8, but they will arrive as separate apps, instead of being integrated as what you see with Windows Phone 8.
Voice Command, Bing Audio, and cloud services will remain the same all the way from Windows Phone 7.5 to Windows Phone 7.8, althoug those who are rocking to Windows Phone 8 will be receiving more powerful versions of each software though.