Quoting a few comments on the new design screenshots I made on IRC:

1. The post header (author / date /etc) can be shown in a single line
2. The post header does not have to be white, I would go for a thin 1-pixel frame around post header+body and a thin 1-pixel line separating header from the body. This way it is clear which header relates to which post.
3. The number of top menu items can be reduced and their font size made smaller - right now they are bigger than titles on those shots.
4. Stuff like Bugs, Talk FAQ, Buddy List, Member List does not have to be there on top. These items are rarely used.
5. For the top menu bar I would leave: Home | New | Today | Mark Read | User CP | Subscriptions
6. For width-constrained mobile version, "Mark Read", "Today", and "Subscriptions" can be dropped from the top menu.