UPDATE - 10/24@9:25PM: Since the cat's now out of the bag, Rush sound engineer Rich Chyckichimed in via Twitter to admit that he's been working on the 5.1 remix of 2112:
Yep, words out. I've been working on the surround remix of #Rush #2112 for months. Queue rear waterfall. #holygrail
So this seems to verify that the reissue will indeed contain a 5.1 surround sound remix of the album as we had guessed.
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According to a post at MusicTap.net, Mercury Records will reissue a Super Deluxe CD/BD version of Rush's classic 2112 album this coming December 18th. No further details were given, but one would assume that the release would include a 5.1 version of the album. 2112 was included as part of the Sector 1 box set release last year, but no 5.1 release of the album was included. More details as we learn them. Thanks to John at Cygnus-X1.net for the heads up.