Some interesting numbers have been published by Dev4Press.com which show just over 50% of sites reporting data back to the WordPress.org mother ship are registering as using version 3.0. 10.8% for 3.1 and 16.2 percent use 3.2. When looking at the big picture, those are terrible numbers. That 50% number would ideally be 3.2 but for any number of reasons, those websites are not being upgraded. There is also the issue of accuracy in that many of the websites that are being reported may have either been abandoned or left online as a test bed.
I’m sure many plugin authors can relate to Millan in that supporting 3-4 versions of WordPress can be a pain in the neck considering some of the major differences between versions. What’s a plugin author do so since leaving those users out to dry is not acceptable?