With the advent of CSS and XHTML, markup can now be semantic (notice lowercase s)- it can have meaningful structure which is independent of how the content is presented in a browser.
So, we already have a web- a web which can be used to create semantic content, yet is, at the same time, presentable to users in its native form. As Tantek elik has said, users first, computers second.
…deemed microformats are appearing. These standards specify ways to markup XHTML in ways that give the content some meaning. Some examples include: Votelinks, NoFollow, hCard, hCalendar, podcasting, blogchalking, geourl, xfn, license, RelTag xFolk, and online news.
The promise of microformats is that they offer machine-usable data while at the same time providing human-usable, presentable content.