I subscribe to the Lefsetz Letter, and a recent email detailed Lefsetz talking to Bob Seger at a party. Seger apparently said he was doing a tribute album to Glenn. Here's the quote from Lefsetz:
"Bob starts talking about his new album, cut in Nashville, a tribute to Glenn Frey!"
I did a little research and didn't turn up anything else yet, but I only looked a short while.
Of course, perhaps I misunderstood, or Lefsetz misunderstood.... if anyone else hears anything, put it here!