Well, the official NOI isn't available publicly yet - a spokesperson for the FCC said it would be available on the internet in a couple of days. Of course, that doesn't stop them from putting out a press release: FCC Explores Rules for Digital Audio Broadcasting [PDF].
As rumored, the FCC is going to start the process for considering a broadcast flag rule for digital radio (among a lot of other changes as well):
Subjects raised for comment in the Notice of Inquiry include digital audio content control and international issues.
The subtitle of the press release is: "Goal is to Promote the Introduction of Digital Radio Services for Americans."
That sounds awfully similar to what they said about the television broadcast flag. I'll provide full details on the NOI when it is available.