Larry Larue's piece today suggests that Miguel Olivo will be sent to the minors while the team looks for another cheap veteran catcher to take his place on the roster for the time being. Rene Rivera will be promoted until said catcher is found, and Pat Borders (I'm serious) will thus take over the starting role.
In terms of on-field performance, anything the Mariners do will improve the team - Olivo's been horribly bad to the point where the team could play any living, breathing, at least semi-conscious mammal behind the plate and gain a bunch of OPS. As far as Olivo's development is concerned, though, these sudden demotions rarely do anything to help a guy's long-term ability. You could argue that Gil Meche benefited from his AAA vacation last year, but he's not exactly lighting it up right now; off the top of my head, only Roy Halladay comes to mind as a guy who really picked it up after being sent back to the little leagues. Pray for Olivo, but don't expect too much.
UPDATE: It's official. Rivera up, Miguel down. Good luck Olivo, get your swing back.