Couple of things...first I don't think that Staal and Semin have been playing badly per se. Their timing is off. Look at how they set their plays up, when the passes occur, how the passes are just a bit off. The issue on this line has been the confusion that is Jiri Tlusty. He seems to have forgotten what he did well last year: fight for pucks in the corners, get them to Staal and Semin, and then move in to scoring positions. He's also just not as tough on the puck (but he can be). I thought Staal had a couple of brain cramps last game and so did Semin, but it wasn't a lack of effort or an emotional let down IMHO. I think it all is timing. That will come.
Because of this, I think putting a solid guy like Ruutu (or perhaps even a Gerbe) on that line makes good sense. Also, I think moving Tlusty down to Jordan's line is a great idea. I think he's a bigger body than Dwyer, just about as defensively responsible, and once he gets his mojo back, won't get knocked off of the puck as easily as Patty does. A second line of Gerbe/JStaal/Tlusty is filled with 3 potentially solid scorers (not flashy but solid) and 3 very good defenders. If Tlusty gets back to what he did well last year, he'll get some rebound goals, push the puck to Gerbe for close in goals, and hopefully allow Jordan to cycle and crash for rebounds too. I like this line construction.
I hate the line of Skinner/Nash/Dwyer. The 3rd line currently excels because of the calm, erudite decision-making of Dvorak. He's the "big toe" that makes the 3rd line work. I don't like taking him off unless they've got a similar player to put on that line. Dwyer is a lot of heart, a lot of effort, and speed to burn but he's not really a great passer and his shot is only adequate. Defenses will collapse on Skinner and the combo of Dwyer/Nash isn't dynamic enough to be problematic for our opponents. I'd like to see that line left alone until Elias comes back. I'd even put Bowman on that line before Dwyer.
Meanwhile a 4th line of Bowman/Sutter/Dwyer is something that I like. Bowman and Sutter bring some grit and Patty Dwyer's got lots of speed and hockey sense. This line can cycle and be solid in their own zone. Bowman and Dwyer can get pucks out of our zone and press the action. Sutter can be a net presence. All in all a very solid 4th line.
Just my two cents and why I think we're close to getting the lines right.