Without having seen much of Onyewu (just the Confederations Cup), what I know from now, and it's a quality, is that the guy is smart ...
By doing such a thing, he probably knew he would be rated a lot more higher by fans and the club (suddenly, we don't care anymore about his level, like if he had a great season and showed to all of us that he was as good as Nesta or T.Silva on the pitch
), and this way, he just allows himself to stay in a "big" club (some could claim we're not big anymore, I will reply it's just a matter of time, maybe even after this summer if the right moves are done) one more year.
After reading the article, I even thought it would be good to have Onyewu as vice-T.Silva or vice-Nesta without any particular reason !!