You could format a letter stating what it is retailers would like done about the kids comics issue, and at the end of the letter you could leave a spot for people to leave their info.  Then you could e-mail said letter to all your e-mail list members telling them to add their names and company names to the list of others who agree with the letter, then you can forward those emails to the big companies.  You could also print out the letter and the names and snail mail it to the companies or drop them off with their reps at the cons and trade shows.

I agree with the fact that there need to be more kids comics out there, but let's not forget the ones that are out there already trying to survive in a market that isn't trying, in many ways, to help them out.  Players such as the Archie lines and the Herobear and the Kid-type comics are out there; we just need to showcase them more, and then maybe some of the big companies will start making more kids comics.  They're all about making a buck, so if they don't see any green they won't make the books.

We're mulling this over.  Thanks for the suggestions.
-Ed.