The rewards curve is changing. We expect posts that would make more than 20 STEEM under the old rules to earn more after the changes. Those posts that would have made less than 20 STEEM under the old rules will receive less after the changes.
I see this as highly unlikely. With the current distribution of rewards, I would expect posts that earn more than 50 Steem under the old rules to earn more and posts with less than 50 Steem to earn less. If rewards become far more evenly distributed between posts, this 20 Steem equilbrium between curves is possible. This would require far less use of bid bots, limited circle jerking, and frontrunning.
On a positive note, the rewards will only be slightly lower. I estimated a reduction of about 2 Steem for posts earning around 15 Steem under the old rules. This is not taking into account SPS and 50/50 curation.
Most non-linear curves have this problem. Sigmoid curves are less problematic in this regard but create other strange relationships depending on voting patterns. I wrote about the 2e12 rewards curve about 2 months ago in my post 'Taking a closer look at the EIP 2e12 Reward Curve'.