http://storefront.steampowered.com/Steam/Marketing/message/1125/
''We're now in the home stretch on getting everything finished off with the Orange Box games. Just this week, we've finished recording and placing all of the developer commentary for the three new games. Episode Two, Team Fortress 2, and Portal together will include over two and a half hours of new commentary that should help shed some light into the thinking and challenges behind these three new games. This is all in addition to the hour or so of commentary included in Episode One. Commentary will be included on all three platforms (PC, XBOX 360, and PS3)''
Seems like they are almost done
''We're now in the home stretch on getting everything finished off with the Orange Box games. Just this week, we've finished recording and placing all of the developer commentary for the three new games. Episode Two, Team Fortress 2, and Portal together will include over two and a half hours of new commentary that should help shed some light into the thinking and challenges behind these three new games. This is all in addition to the hour or so of commentary included in Episode One. Commentary will be included on all three platforms (PC, XBOX 360, and PS3)''
Seems like they are almost done