Hello,
this might be an inappropriate subject for this list, but I'm one of those people who still believe in a binary solution (not necessarily a binary/efficient XML). You know... Because of performance, storage capabilities (see http://xmlsucks.org) and I don't believe, that English is so perfect, that it will be here forever, and with unchanged meaning for tag names.

Therefore I would like to ask how wide will be an efficient XML used, like will it be just an alternative for special cases (mentioned in the Binary XML Use Cases http://www.w3.org/TR/xbc-use-cases/ ) or might it be possible to use it as some "compression schema" for web browsers as well or, in an extreme case, will it be used for all documents and shift regular XML to be just a textual interface?

Well, I like the XML as a textual interface, but I don't like forcing data into it just because we can spare time on programming special tools. I think that providing such tools instead of using simple text editors will be worth gained performance. I also think, that the XML have to be thrown someday as the text will become obsolete, as for example with a direct brain implants communication or whatever... It might happen, right? :-)

I personally prefer an opposite way than the XML binarization. I would rather construct a reliable binary format with XML-similar textual interface and hide it as a sublayer. I did some work on my own alternative binary format already. It is in a planning stage and it isn't even completely translated yet: http://xbup.sf.net

Best regards and sorry for my non-perfect English,
HajdaM, Czech Republic