The Steve Rubel Stream

"Users like the simplicity of messages that pass into oblivion over time, but were frequently frustrated by unscannable writing, overly frequent postings, and their inability to locate companies on social networks."

Some of this is easily fixable, however ...

"As the satisfaction ratings indicate, we have a long way to go to improve the usability of social network messaging and RSS feeds.

The problems start with something as simple as the choice of username. For example, the United States Department of Education's Twitter ID was 'usedgov,' which sounded to users like 'used government' and was off-putting. Logos were often bad as well, particularly in the small rendering that some services offer. Users depend on the ability to scan down a stream to pick out logos and user names, but this basic need was often thwarted."

This is why email in business isn't dying anytime soon. For consumers, however, things might be different.