I don't really get the impression that it has any impact in the contemporary art world, although I would love to be proven wrong.

The closest thing I can think of was the recent Tumblr Art Symposium: http://hyperallergic.com/tumblrart/

deviantART has a reputation for being the most lowbrow of the popular art sharing sites on the Internet. It's all comics, bad photography, and fanart. No serious artist would put their work up there. Flickr is slightly more respected. Tumblr has the most respect among "real artists". Good coverage on the intersection between art and tech happens at http://rhizome.org/ & http://we-make-money-not-art.com/.

this is definitely not true, although the focus is definitely on illustration/concept art/comics. there are some fantastic artists on deviant art.