The limiting factor on worldwide jamming is the speed of light - which is fast, but means enough delay to screw up certain kinds of ensemble stuff. So, I'm a fraction of a second behind you, but then you're a fraction of a second behind me.. Could sound quite interestig though.
At present there's so relatively few of us about we're back to having music made by a smallish community, and ignoring a lot of what's going down around us. The technology just means the small communities can be quite a bit spread out, and keep in touch with each other. And I think that's just the kind of setup in which traditions put down roots, grow a bit of foliage and produce a fair crop of fruit.
I reckon that, by and large, the quality and range of the music being played is far higher these days than it was during any of the big Folk Scares.