except anything you can build today will be slow and tiny capacity tomorrow. the fact that anyone could suggest a universal format can be developed that will endure all of time where everyone continues to use it for ever after it is introduced is farcical like a fairy tale where unicorns exist.
I would imagine that the express purpose for this format would be exclusively ultra-long-term archival and that it would not see much if any day to day usage, similar to tape drives now (but on a much longer timeline).
For this purpose speed and capacity aren't as important because we've had great information density for relatively small file sizes for a long time now. A ridiculous amount of information can be stored in just plain old text files, especially if compressed. For video and audio, recordings in even just 128k AAC and 720p h.264 video would be a wonderful thing to have 100+ years from now; anything better would be a cherry on top.
That's interesting: it focused on XML/SGML formats, but gives no mention of TeX (specifically LaTeX) that's pretty big in natural sciences and publications. It also seems trivial to reproduce with the base tools being free software and pretty small.
