It would be nice to have support for the Opus audio codec.
The big advantage here is that Opus is a pretty good speech codec at moderate bitrates (near-transparency for speech claimed at 24-32kbps), which can save a fair bit of space for voicing.
It also achieves similar quality at substantially lower bitrates vs vorbis &c. for general audio. Some other properties like latency which could plausibly be useful if someone wanted to implement in-game voice chat, I guess.
License is identical to Vorbis, so it shouldn't be a problem.