I've been doing some looking and haven't come up with much other than the 3D techniques. I personally have always liked the look where it does look like you've laid out things on a floor or whatever, but I am using fabric.
We have so many variations on what is a quilt. For me, a quilt is a craft -- that is a usable object. My old tag line on my previous forums was something like "It might be made of three layers, but if you can't wrap a sick baby in it, then it's not a quilt!" but that is only my definition.
I'm fascinated by what I call the textile arts, the many things other people do that I don't -- the wall hangings, the truly three-dimensional, the indeed quilted objects that are too delicate for a sick baby. And the artists that work in fabric. We don't always understand art and statements, I feel I have too explain too much for my statements in my quilting to be understood to be art. It's like jokes -- if you have to explain it, it ain't funny. But for me, I know and it is enough.
So in Art Quilting that goes a step beyond Modern. People who are stretching boundaries out of squares/rectangles and challenging our concepts or making us re-examine our assumptions. I have seen quilts (in a museum show!) that included organic/decomposing waste. Interactive quilts with pockets. Quilts with holes, usually for meaning (often broken hearts) but sometimes mostly aesthetics. I seem to remember an infinity symbol made with Y2K pieces? At least a lot of little pieces, two holes, and the figure 8 shape, no straight edges except the seams.