The NCS, from what I’ve heard, seems to have always been behind the trends. It’s just that, with less barrier to entry, we are seeing more indie stuff, and the high number means that even it is evolving.
One of the most experimental webcomics I’ve seen to date has been MSPaint Adventures. It is not only experimenting with a one panel format, with all talking done below the image (including some really long conversations), but also includes every other panel being slightly animated, full out motion videos, and even interactive pertions. The story itself is also experimental. It was designed from the beginning to be a sequential story, yet the author only had a few things specifically planned. It uses a lot of time travel, which simultaneously allows for a lot of freedom and a lot of restrictions. Nearly everything in the story is either a reference, foreshadowing, or call back, and yet it still makes coherent sense. It is somewhat meta, plays with a bunch of tropes, taking them in new directions and subverting expectations. The only real downside is that the author is about as unskilled in the actual mechanics as the writer of Twilight or Eragon, but he mostly avoids his limitations with his format.
Well, that and you may not find the experiment itself rewarding. He definitely isn’t playing it safe. But it’s definitely on the edge of showing what a webcomic can be. If traditional comics could take even some of it, they would be a lot better. NCS really can’t hope to be what it needs to be today until it embraces the experimentalists.