With the arrest of Ryan in this past week's season finale on The Office, the show might have jumped the shark on the only character arc worth following in season 4.
I found Ryan to be boring in Seasons 1-3, but he became immensely interesting this past year. I find him incredibly relatable to real life for a lot of us young 20-somethings, who see some of our less intelligent peers excel through the ranks very quickly and let it get to our head.
Beyond that, Ryan was the only truly dynamic character in Season 4. Dwight has softened up over the last 2 seasons and has gone from stiffie to sympathetic figure but a lot of that was last season and some of the better characters had their coming out parties in prior seasons where they developed personality and became interesting characters: Oscar in season 3 (where he literally came out), Meredith in Season 2 revealing her alcoholness, Angela in season 2 and 3 revelaing her insanity, Dwight in season 3, creed in season 3 with his creepiness, Kelly in season 3 (the customer service episode especially).
The problem here is that the show aims for realism so the writing staff has to make sure the characters aren't overly dynamic, undergoing humongous character arcs. The only option in turn is to bring out interesting facets of characters, and the writers have done the best job with Ryan. I know we don't like Ryan as a person, but I loved where the character Ryan went this season as a study of absolute power corrupting absolutely.