Gmail filter feature wanted

I’ve been moving a fairly large part of my private mail to my Gmail account.  Gmail do have some amazing features for searching, labeling and handling mail and the virtually unlimited storage is also pretty cool - Much cooler than keeping a huge mail-archive on an IMAP-server or having it on a local fragile hard disk.

One of the more recent things I’ve started using GMail for is backups of this site. With the wp-db-backup plugin for Wordpress a backup of the entired database is mail to my gmail account every 24 hours and using filters I’m applying a ”backup”-label and auto-archiving it (and avoiding noise in inbox).

While this works great, I’d like to be able to through a filter automatically delete messages older than say 7 days with a certain label. This could help me remove old backups automatically – and also clear-out mailing list messages (they usually have an online archive, so why waste Gmail space on a copy).

Date-based searching is already available in gmail, so please, someone at the Gmail development staff, make it available in filters too…