There are mixed views on whether things like typical widget areas should be as list items or not. Many people have differing opinions on this.

The HTML5 spec. isn’t released yet, so I wouldn’t like to see HTML5 elements being used yet. Inserting conditional comments to hack around lack of support in IE for not supporting a standard which isn’t even a standard yet is not a good either IMO.

I definitely agree with your sizing and title ideas though.