I can buy ear counts being up in 2004 because a very large percentage of the USA had better than normal planting conditions and weather for consistent emergence.  I can buy planted populations maybe being jacked up in 2009 by the very recent memory of $6 corn (and many of us still delivering it at planting time,) coupled with all the hype about how the "new genetics" will yield at higher populations.  

Given that maybe 40% of the corn belt planted into conditions that were marginal to horrible this spring, and there was no price incentive to max out inputs, some skepticism may be justified about whether it's actually logical to expect higher ear counts.