I’ve taken Ashwin Bihari’s old Auto Delete Posts plugin and made the necessary modifications to make it compatible with WordPress 2.1.2.
SQL queries have been modified so that it excludes pages and the first two Category ID's. They will now not show up in the admin for deletion.
Get it here: http://digitalwestex.org/category/wp-plugins/
If you have any problems or questions, email me here: 2notch at cableone dot net