The first update for Windows 10 Technical Preview included over 7,000 improvements, many of these new changes came from feedback by users on the Windows Insider Program. One of the new improvements we’re now learning is that Windows 10 will ship with two new media formats: MKV and HEVC.
Windows 10 MKV support: This is a popular open standard container that is picking up speed on high-definition videos. In Windows 8.1, users still need to install extra codecs or download other software such as VLC to be able to play MKV video files, in Windows 10, MKV will come baked in without extra software or configuration.
Windows 10 High Efficiency Video Coding (HEVC): With the fast-growing adoption of 4K video, it’s necessary a video compression standard for better video quality while keeping file size smaller. HEVC, also refer as H.265 seems to be answer and successor to H.264 video compressor widely used today, and it promise to be have optimal video quality as H.264, but with better file size control.
Although, Microsoft decided to remove DVD playback support for Windows Media Player in Windows 8, in Windows 10 the software will now play natively MKV and H.265 file formats without the need of extra codecs or software.
Source Microsoft (Twitter)