Rewritten new audio core, new anaglyph filter for side-by-side 3D, faster video decoding, Support for fragmented MP4 and Improved MKV support are some of the added features of VLC 2.1 Rincewind. There are few tweaks in the appearance and major upgrades in performance, support and functionality.
See complete features of VLC 2.1 Rincewind on VideoLAN