I realized this morning that my metric in Cutting Off the Leeches was wrong. I see Perl 5.8.7 and Perl 5.8.8 as different major releases because of the Perl 5's development model.
Anyone else who thinks that is probably also on p5p.
After realizing that, I now find it reasonable to support the latest point release of the previous stable major version of Perl, as well as the current stable major release. Instead of Perl 5.8.3 (and instead of using its age as the cutoff point), my new oldest supported version is Perl 5.6.2.
Now if a module or distribution needs a new feature only present in a later version, I'll mark that specifically... but I can live with supporting Perl 5.6.2 (almost four years old) until Perl 5.10 comes out.