Are we watching the same Timonen here? I wouldn't say he is here to fill the Sopel role, he isn't overly physical, wouldn't consider him a defensive dman (more offensive if anything), and he is good at blocking shots but nothing ridiculous.
If Timonen can come in and play, this could be a good deal. Timonen has a pretty light contract so there is still plenty of room to add. Big question here is what are the Blackhawks doing with their blueline now? TVR is in the AHL and Rundblad, Erixon, and Cumiskey all would have to pass through waivers. Wonder if the Blackhawks simply risk losing one of those players.
Deal could go any way here, seems like a bit of a high risk/high reward...but I don't know if I would agree with your assessment of the style of hockey that Timonen plays. He has a nice overall game but I would consider him more of a offensive Dman and he will likely get a look on the PP right off the bat.