So, I have a problem with the hype surrounding "Web 2.0" , which is mainly that it's not as new as everyone claims. Definitely, it's a new ballpark from the first round of websites, which were (for the most part) static, clunky, and non-interactive.
Nevertheless, the wonder and excitement of Web 2.0 reminds me heavily of the early days of the Internet, and the non-web parts of it -- BBSes, Usenet, and the command-line interface world of remote-login Unix boxes. IM and chat rooms were possible through the "talk" command, shared social spaces (created often wholly by more senior members of the community) existed in the text-adventure world of muds/moos, and blog-like posts made it into early webpages with cheerful (at least sometimes) banter going on through guestbook scripts or email that the authors could post to the original article.
It seems that the main difference is that the new communities are a smaller chunk of the net community; the overall size of the net has expanded so greatly that the utopic community that Barlow et al saw became unsustainable and beyond the scope of anarchy/self-regulation for the entire group (I was tempted to title this entry "The Myth of Sysopus" after the legendary role that someone dubbed a sysop/wizard in the earlier days had).
But this need to form communities has re-expressed itself, and the interface is blissfully better than (ok, for the most part) what we had to deal with before. Of course, for the larger/more global new/web 2.0 communities, we have to wonder if we'll go through another round of fragmentation as they themselves outgrow their ability to self-regulate. Wikipedia has received its fair share of criticism this past month for inaccuracies; but, I think this is overlooking the vast amounts of valid and quality information -- and only a first inkling in the eventual hassles it will face.
But what does this all mean for development?
This lower bar for getting information and forming communities through the net brings in a lot more noise (think myspace/facebook), but it also enables some minimally tech-savvy types to get an easily-maintained presence online and benefit from a kind of global cost-sharing of development/hosting/problem solving through F/LOSS (open source) tools, hosted, ad and member-supported apps like Flickr and Blogger