Some else I seem to have noticed this week.
My normal method of working with the forum is to go to the "content" tab and read the messages from the bottom, up (oldest to newest) starting with the message that has a 'last update' timestamp that is about the last time I checked. If I reply to a thread, I just hit the browser (Firefox) back button to go back to the content listing. In the past (with the new forum) this seemed to force a page refresh, because the thread I had just responded to would have jumped to the top (newest) of the list. Now when I go back, it seems to get the page from local cache, as all the threads are still where they were.
Not that one is necessarily better than the other, but the change obviously indicates, well, a change.