Wikipedia will probably outlive most personal sites, and will be the subject of much more analysis. I would be somewhat surprised if on net, over next decade personal benefit captured greater for effort put into Wikipedia and similar edits than equivalent effort put into personal site. One step in this direction would be better tools to illustrate one's contributions. I've only seen people list articles they've contributed heavily to.

But much of the web will be subject to similar analysis, just less concentrated, and ability to capture private benefit from personal site also problematic, just less so. Putting effort into one's own site has more similarities to editing Wikipedia than differences. I realize that's a fairly vacuous statement. :-)