Current situation is about 50 blogs running on WPMU, RSS feeds and iframe content.

Obviously we need some exclusive content to include on each domain.

The question is HOW do we automate this part? Is there some way to generate/modify additional content automatically? If not, what is the least time/labor intensive way to accomplish this?

Right now the choice of creating 50 WEEKLY exclusive content items seems overwhelming . . . let alone as the network of blogs grows!