In anticipation (dread) of the Net Aesthetics 2.0 panel* went back and looked at a series of posts I did on "the blog as delivery system for art" vs "stationary sites that critique the web."
These grew out of a New York Times article in 2004 on the topic of whether Net Art was dead.
The post about the New York Times article (and comments).
A first stab at defining the earliest surf clubs, in 2004: "These largely basement producers handle Net graphics in a painterly or expressionistic way, cocking a half-appreciative, half-horrified eye on all the weird content out there on the Internet. The phenomenon isn't about marketing (yet) but rather thrives within the Net's potlatch or 'gift economy' of upload exchange. Artists put up simple animations made with .GIFs or Flash, with sound or without, as well as appropriate, resize and mutate found .GIFs and jpegs, attacking visual phenomena the way a junglist attacks sound (to make an electronic music analogy). Rebellious defacement and smartass humor trump the tedious academic-cum-Sol LeWittoid pallette of earlier net practice."
Follow-up to the above, 2004: "Early Net Art was made by software writers who knew their way around the enabling programs, hence the prevalence of flow charts, clickable steps, etc built into the art. Now, more artists are just working with the tools (image-making, sound-making software) and using the Net as a delivery system. This newer work is less about commenting on, reproducing or 'deconstructing' the tools, or the Net itself--although those concerns do (and should) linger, since proprietary programs are controlling and kind of evil."
Thoughts on the first Net Aesthetics 2.0 panel, in 2006. Written without having attended the panel.
From the Rhizome 4chan thread [afterthoughts in brackets]: "My  comments about the blog as delivery system for finished artwork were made pre-YouTube and pre-surf clubs [or pre-Nasty Nets, since arguably Linkoln, jimpunk, et al had a surf club with 544x378 (WebTV)]. Things are potentially much more communal now [because of all the social bookmarking and corporate file-sharing sites]. Though I've never been comfortable with YouTube's 450 pixel scrunch, and now that the Kitchen is doing "gallery artists who use YouTube" (this from Rachel Greene, who seems to have fled her net.art years as fast as her Segway can carry her) I really want to flee, too. 544x378 (WebTV) was about finding things on Google with those dimensions (among other things), not shoehorning things into them..."
*Update, 2011: The Rhizome link has been changed to http://rhizome.org/editorial/2008/jun/2/net-aesthetics-20/.