Any word on this? I'm sure there is a <tr> or something somewhere I can change get the layout I'm looking for.

*edit*

The image seems to have stopped working. In that above post I'm referrin to the white space below the profile icon (and on the left of the post itself). It seems like a lot of wasted space, and for long posts makes the post itself look pushed over.

Wow, suprised this wasn't answered before. It's been a long time since your post, but perhaps someone else could find this helpful.

The file you need to edit is the following:

mod/groups/views/default/forum/topicposts.php

It controls the layout of the forum topic posts.

Good luck!

After thinking about this idea a little bit I had a go myself and managed to change the layout of forum posts to this. It's actually very easy to do. I also added in some links to the post_owner's content on the site to make it a bit more colourful. One thing about out-of-the-box elgg is that in my mind it's decidedly bland. 

Editing the file I mentioned above is really easy to do. If you know basic php and html you can do it no problem. It's only a table.

Good luck!