Oh yeah bing, that's definitely the heart of it all -- who the hell ARE Charles Widmore and Ben Linus, and why are they mortal enemies? On the surface of it, Widmore fits the hollywood stereotype of the wealthy megalomaniac badguy nicely, without the cheese of any of James Bond's arch enemies, and I'd venture a guess they were once allies and friends for a common and controversial cause (the Dharma Initiative?), until one fucked over the other somehow.
The increased action has definitely made for a tenser watch every Wednesday night before I go to work -- long gone are the days I'd float into work on this peaceful image in my head of Hurley driving an old VW bus with 'Halls of Shambhala' playing in the background. The action isn't gratuitous or overdone, but it definitely has changed the mood of the show.