I think last years Janish is the "real" Janish.. what would should expect in 2012. If others disagree, I can understand.
But if we go under the assumption that the rest of the league has figured out how to render Janish totally hapless (521 OPS, like last year), then it makes sense to add another SS. Valdez is no one's dream SS, but he's an upgrade to a 521 OPS SS who is average at best defensively (My opinion of Janish, which I think Walt shares).
Considering what we paid for Renturia last year, paying around 900k ish for Valdez is not an excessive expenditure. It's probably a better fit for us than Theriot.