David Booth and the second line.
Scoring tonight, David Booth has four goals in six games. When he hasn't been adjusting to his new team or getting back into game-speed after his injury he's been quite the explosive goalscorer. He's a tad one-dimensional but when that dimension is scoring goals and it's working, you can overlook things like defensive decencies.
Which brings us to the second line. It's awesome, perhaps the best secondary scoring since the Sedins were "promoted" to first liners. Kesler finally has competent wingers instead of a rotating cast of cast-offs. David Booth, as mentioned, is sparkling, Chris Higgins is the hard-working Canuck and great at disrupting the play and playing the puck, and Kassian adds another wrinkle as well.
David Booth could be a very key component come playoff time when the Sedins are facing the brunt of attention and Kesler can't do it all himself. Think Mikkael Samulesson a couple years ago only more competitive.