From an email that I received from B5 books last March 19:
WHAT THE HELL HAPPENED?, Volume 2 is planned for release after the re-launch of B5books.com.
J. Michael Straczynski, being painfully aware of the lag in the CRUSADE book release schedule, is putting together a "thank you for your patience" bonus that makes it worth the wait: he's producing his two unfilmed CRUSADE episodes as audio dramas with "voices the fans are familiar with." The audio drama episodes are "To the Ends of the Earth" and "The End of the Line".
Since neither of these unproduced scripts are in Volume 2, one CD will be included FREE with Volume 3 of WHAT THE HELL HAPPENED? and the other CD FREE with Volume 4.
Reminder: ALL CRUSADE books will be available until the HELL series is complete.
ETA: I'm not sure I want to spend £20 per script book to obtain each of those CDs. I'd willingly pay say £5 to download MP3 versions, however.