Back in the day, in discussions among your friends and fellow fans, when an album came out that was a double or triple (or more) vinyl album, did you say things like "oh this song is my favorite off the first vinyl" or "the second vinyl isn't as good as the first"...or were these albums treated as unified whole pieces (which, IMO, as they should be).
I think in the era of the CD, fans are quick to dismiss the fact that some double albums are meant to be single pieces of works, but the time limitations of CDs don't allow some 80+ minute releases to be on a single disc. And because of the portability of them, it's easy to just bring only half an album along. With vinyls, it was easier to listen to things in one go - a 75 minute double album would almost HAVE to be done in one sitting (for those who DO listen to whole albums), just because you're already there investing time in putting on the vinyl and setting the needle - it's almost ritualistic. With CDs, you just slide it into the player and it plays.
Fortunately, in the digital age, it's easier to let a whole album play without having to worry about changing vinyls or discs - it just plays if you let it, so I think the idea of "double albums" might be phased out if digital music remains a popular (and growing) medium. Every major release would just be an ALBUM, as the terms of double and triple only hold meaning to the medium upon which the album is on - for example, The Who's Tommy was a double vinyl LP when it was originally released, but now it's on a single CD.
And as much as I would hate physical formats being phased out, I think it would be there wouldn't be anymore arguments about "which disc is better" in a double album - all albums are single units in my eyes...but then again, this is from a fan who listens to a LOT of music that spans 2 CDs.
-Marc.