DivX Labs has released beta 1 of the DivX 6.4 Codec. Along with a new 1080HD encoding mode, this new version of the DivX Codec includes features like faster multipass encoding, high efficiency resize filters and adaptive noise reduction.
DivX Codec now includes a 1080HD encoding mode allowing you to create full size 1920 x 1080 resolution video in high quality DivX format. Videos encoded using this new setting are suitable for playback on fast desktop computers and are more likely to play on future hardware devices than videos encoded using unconstrained mode, and unlike unconstrained mode, 1080HD encoding will be available for free in the DivX Community Codec. Both 1080i and 1080p encoding is supported.
More information on the DivX 6.4 Codec can be found here. That page also has a download link if you want to try the beta out. Feel free to share your experiences in our forum.