While Lopez's bat this past season finally started to resemble the one people have expected him to show for so long, all year questions were raised about his performance in the field. There seemed to be a growing consensus that his combination of size, mental mistakes, and perceived effort issues was finally catching up to him and making him a problem at second base. Lopez's defense, some have said, was bad enough that it negated a significant chunk of his offensive improvement.
As it turns out, there's no statistical indication of a collapse. While as always I will concede that the numbers may be wrong, the evidence is pretty solid that Lopez was perfectly adequate with the glove.
UZR: no sign of being horrible
+/-: neither one of the top nor one of the bottom second basemen
Overall team stats: Mariners weak to bad, but not extraordinarily so despite known glaring problems in Sexson, Yuni, and Ibanez
I'm not going to sit here and claim that Lopez hasn't gotten any worse. He probably has. Nearly every player's defense gets worse as he ages. But there's a difference between "declined" and "big giant suck", and the burden of proof is on those that say he's no good, because I'm not convinced. This team may have more problems than Ezequiel Astacio's complexion, but I'm not yet ready to believe that Jose Lopez is one of them.
Yuni is though. Yuni blows.
edit: I should add however that I'm all about dealing Lopez if a good offer comes along. Just because I think he's useful doesn't mean he shouldn't also be trade bait.