I just checked the last page of some topics that are on the top of Announcements (Altcoins) board. Except a few ones, all of them include posts by high-merit users. Now at the time of writing a random topic which has posted in 2014 and has not received any reply is on the second place. I think one of high-merit users has bumped that only for testing. (It's great that it is affected only in 36 hours)
It's great that I can see the threads that are of interest to high-merit users.

two suggestions:
-Now the effect of clicking on the "bump" button is 15 times the effect of making a post on a thread. As a user can give bump score to a thread once per 24 hours by clicking on "bump" button and once per 7 days by making a post, the effect of clicking on the "bump" is much more.
I suggest to decrease the effect of super bumps.
-A bad review shouldn't help a thread bump. So, users should be allowed to make posts on threads without giving them bump score.

Edit: Now it's really difficult for new topics to be on the top. I think the effect of topic starter can be considered more. In this case, If a thread is started by a high-merit user, it has a more chance to be on top at least for 36 hours.