Twitter is only useful because "normal" media makes news about notable tweets.
I surely don't get my information from twitter. Would seem silly to get all my information (or "important" information from "powerful" people) from a hundred character sound bites.
When people talk about getting their news from Twitter, they don't literally mean they never leave Twitter for information. 140 characters is enough for a headline and a link; you click through to articles that interest you.
