EPUB, SchmEPUB. Blablablabla.
One of the things I hate most in IT or computer-related stuff. Nobody can ever agree, because there's a zillion way of doing things. In the end, we just have a zillion different systems, of which only very few people have any real in-depth knowledge. Then, just before one of those systems can actually become THE real standard, one or another thinks it should be done in yet another way, and it starts all over again.
As I've said in other posts, I'm re-ripping my CD's into FLAC. Some people have asked me why I don't use ALAC or APE or whatever. Why? Easy.
FLAC is free, it's not covered by patents, it has been stable since 2007 (now in 2013, an update has been released to make it easier to compile, using newer compilers), it's crossplatform running basically everywhere, it can be used from the command line or through a GUI, it has good compression, it's supported by quite a lot of hardware, most audio-related software, and it's the default standard to sell lossless music.
Why the hell do we *NEED* anyhting else? FLAC does everything already. Other standards improve only some very infinitesimally small points, while having some great disadvantages to offset those.
For digital music, this is what counts:
Uncompressed: WAV (AIFF for Apple)
Lossless compression: FLAC (ALAC for Apple stuff)
Lossy compression: MP3, Ogg Vorbis for the open-source minded (AAC for Apple stuff)
If you discount Apple, who is almost always different because of just wanting to be different (which is the reason why I avoid buying stuff from them), the only relevant formats are WAV, FLAC, MP3 and Ogg Vorbis. All of the rest is just dabbling in the margins, IMHO.
I am of the opinion that it's the same with EPUB. Compared to AZW and EPUB (and iBooks...) everything else is irrelevant. Instead of screaming for new standards al the time, I think the book industry should follow the music industry's example, and develop EPUB into a solid, stable standard (and ditch the DRM).