Sports is always good filler - maybe take a Let's Play of a sports game campaign (bonus points if it's Blood Bowl) and write it in a shorter sports journalist style?
From the more advanced planets, socialite gossip is always good, as would be the latest traffic/pirate reports.
On less advanced ones, maybe news of bumper/poor harvests or new mineral resources found, giving rise to business opportunities/hooks.
On the more humorous side, you could do a column of Techpriest Aeolus' technical guide for laymen (substitute various Dilbert strips, re-flavoured for 40K and add more incense and candles).
Sister Kalama's (of the Adeptus Sororitas Order Hospitaller) agony column?
Originally Posted by GolemsVoice
But what if it's true?
Bonus GrimDark points if the good Father has stumbled on a genestealer coven and is now infected. You could do a couple story sections of the Father's spectacular fall from grace and subsequent retirement into seclusion, then his coming back with a new reformed cult of the Emperor, with a message of the sinful to redeem themselves in the Emperor's light (the Father should know, right?) and has an amazing conversion rate of new followers.
Let the story sit for a while, then make mention of the new civil war on the planet and a bit later, the subsequent discovery of a genestealer infestation (which the players can either join in on the shooting, help supply Imperial forces, or steer well clear).