I think it would be nice to have sticky posts(similuar to sticky threads). It can be very usefull for threads that have proposal or announcement. So OP's first would be displayed at top doesn't matter which thread page you are at. And he would update only it
Some of announcement of apps thread have over 300 posts and you need to make search thru whole thread or go back to the first page to find up to date info (or new screenies :P ) everytime.
Same with brainstorm. I would like to have proposal and updates of current status on the top of any page in relevant thread.