Topic: More markup (classes, ID's)
It would be great to have more markup to mess around with, both for CSS and JS. An example: A forum I'm working on, eldvakt.se, uses jQuery to get the three newest topics from each forum and display them below each forum. To be able to do this I had to edit index.php and add the forum ID ('f'.$cur_forum['fid'] to be exact) as an id and the class "forum" for each row. The JS is unobtrusive, and gets the data from a modified external.php.
It would've been great if this had been there by default, and also things like topic id, post id, user id and whatever. It's not a lot of work, poses no security risk and won't impact bandwidth, well, not much. It becomes a lot easier to do things like inline editing and other "AJAXy" stuff with it, wich we all like.
Edit: Ouh, and an easy way to add JS would be nice, but I assume that's coming in 1.3.