One short observations which worries me:
people are creating mostly copies of the existing content instead of new content.
Just try to recall how many times you met the same videos, audios, jokes, phrases of the famous people, etc. on the pages of your friends in  the different social networks. Or think about how “unique” are comments on forum and posts in the blogs…

Tanks to Technologies and people who are employing them, video, audio and images are being stored in the same places (YouTube, Vimeo, Flickr etc.), but text is being copied every time.

Here are 2 problems, as for me:

• huge redundancy of the content available in the Interenet;
• decreasing creativity of the people, especially youngsters.

Is it really what DiNucci and O’reilly meant with Web 2.0. Thinking about the amount of repetition it is closer to Web 0.02…