@Andrea_R - Of course we are not to support WP 2.0, issue here is with 3.0 and newer versions.

There is another interesting data in one of the comments in my post on Dev4Press where you can see that overall download of WordPress 3.1 and 3.2 is down as well. This shows that daily downloads average are down 45% with 3.2 compared to 3.1. 13.000.000 downloads of WP 3.2 while high as a numbers go, is disappointing.

People are content to have 3.0, they don't see much point in using newer versions. But, users of my Pro plugins are using latest versions, and adoption rate among them is high. I am sure same can be said for other Pro development companies, and we on our own do a better job introducing new WP and new WP features to our users and they are more familiar with the difference and they are willing to upgrade. On the global scale, education about WordPress is failing. Simply cutting of users with 1-2 years old WordPress versions from new plugins is not a solution. Maybe it is from developers point of view, but 99% of all WP users are not developers.