What's wrong with HTML+CSS? To be honest I wouldn't choose anything XML based, but ODF looks like the lesser of two evils; the OOXML specification is just monsterous.
I'm not sure what reasons there could be to avoid "anything XML based" yet still favour HTML. Can you explain further, please?
These standards don't just cover 'word documents', they also cover other Office types for spreadsheets and presentations. HTML+CSS is a terrible idea for a spreadsheet standard.
The actual recommendation is to use the web for communication, with PDF/A as a second choice for read-only printable docs and ODF is then suggested for editable documents.
Mediocre page break support, just to start with.
(there is some for print media in CSS, but nothing fancy)