Might want to take off the handful of double albums you listed as well - Theory of Everything, Tales, 6DOIT - since I specifically said "single" albums...
Psh...does it matter what designation the album has because of the limitations of the physical medium? I mean, The Who's
Tommy was once a double album on vinyl, but it is now a single CD. Who is to say that in a few years, if physical media still exists for music, that albums like SDOIT and TFTO wouldn't be single albums based on being able to hold 100+ minutes of music? Theoretically, there DO exist some 100 minute CD-R's, so those albums COULD fit on to a single disc, but most people don't use them.
Besides, in the digital-music era, terms like "double album" don't really mean much if the whole album just fits together as one album, regardless of how many discs it is in physical format. As someone who enjoys albums as a whole, double or single, when they're on my iPod, they're one album. I'm not the type to puts "XXXXX Album - Disc 1" separate from "XXXXX Album - Disc 2". Seems kind of pointless when, if released with the intention of being ONE WHOLE album, to keep them separated like that.
-Marc.