The block reward already dropped from 500 to <25 (>20x drop or 4 complete halving), the initial reward formula favored only early adopters that's why (as told in the following comment) it was tweaked a bit the first time https://bitcointalk.org/index.php?topic=421615.msg4675670#msg4675670.
I consider all the changes to reward formula as a way to keep control over huge portion of coins in one or very few hands. Also controlling the largest pool helps promoting any changes.