I don't feel the above comments are based on fact, but rather sound like someone trying to hinder the growth of Perl (mod_perl) or someone that is bitter about their experience with mod_perl.
But in case this node is visited in the future, let me add my 2 cents to the pot.
- All the pieces exist for a Zend/Tomcat type "packaging" of mod_perl, but there are many entrenched users of mod_perl that don't have time to switch to a new methods. One of the reasons being that mod_perl predates (I believe) the other solutions mentioned
- mod_perl is NOT out of reach
- mod_perl is a full open source project which is not directly funded by an organization earning its revenue directly from its sales (use), unlike the two examples you provide. Therefore mod_perl is community/need driven rather then "packaging" driven.