I think sticky posts are very useful in terms of usability. Rather than simply having a title at the top of my categories I would like to have introductions and perhaps an image/icon/specific colours so I can 'brand' specific categories.
At the moment the best way to achieve this is by using the WP-Sticky plugin, or by editing WordPress.
Unfortunately if you use WP-Sticky your sticky posts still display dates, meta info, comments, etc. You can turn comments off but you still get the 'no comments', etc.
I'd like to be able to add a sticky to the top of my categories that is not like a normal post. So in the 'Write post' page (in admin), in the 'Post status' menu, I think WordPress would benefit from having an additional option: 'Sticky post'.
There would most likely also need to be a tab linked to a page devoted to sticky formatting and other options, so you could (for example) choose whether or not you want a title to display in your sticky post -- you may just want text/html because you already have a category title at the top of categories as default.
I would love this option as default, although I expect it could be produced as a plugin. However I do think most WordPress blogs would benefit from short category intros to improve usability, so having this as an option in new WordPress installations would be cool.