To get a flavour for some of the things the Working Group has discussed as a result of reviews you can look at the list of initial comments on the XHTML 2.0 specification (pre-last-call).

We had already worked with the HTML group on such things as removing human readable text from attributes, and allowing the title element to contain markup - these improvements allow for better support of language markup and bidirectional tagging.

Some of the more substantive discussions during the recent review related to the use of quotes, usefulness of the title attribute, representation of abbreviations, use of entities, etc. You can follow the subsequent discusssions in the core public archive.