Just when you think you understand something, then it goes and changes. So true with technology and the web.
Not so long ago (although some would say otherwise), just being able to create your own web page with Notepad or vi was cool (really, it was!). Then the web became more dynamic with HTML 4 and Javascript. Cue up the browser wars next and then - Web 2.0 - the social web! All along the way great debates about usability and design would sprout up. Good design always plays an important role.
Where are we now and is design moving forward into Web 2.1? Sam Solomon blogs about Why I'm Done with Social Media Buttons and gives some insight about where things should be going next.
Meanwhile, the rest of us that are not on the cutting edge just muddle along.
P.S. Not to forget, the concept of the semantic web still exists, it's just not the same buzzword it used to be.
P.S.S. Still might be ahead of it's time, but also check out the Friend of a Friend (FOAF) project.
