It would be nice to allow using CSS selectors as fragment identifiers, so that you can link to things which don't have an id or name attribute. For example:
There's an unofficial draft spec: http://simonstl.com/articles/cssFragID.html
And a community group: http://www.w3.org/community/cssselfrags/
The main downside I can see is that such fragments may be brittle and break if the structure of the page is changed, but this is often still preferable to not being able to use a fragment at all.
It's an interesting idea. Are there any other browser engines planning to implement this? Are there any plans to move this work into a full Working Group?