This past weekend, popular blogger/tweeter Loic LeMeur set off a huge controversy in the Twitterverse by suggesting that Twitter should have a search function which prioritzes Twitter "authority", defining authority by number of followers. Among the many hundreds of responses, Jeremy Toeman of Live Digitally has my favorite, a terrific response synopsis and response here. in which he reasons that number of followers is equivalent to popularity, not authority, and that there are key differences in the two.
Robert Scoble has a smart and scary response here as well where he expresses anger and frustration over "idiots". That popularity could actually be more important than real authority is sad but possibly true.
In the end, searches on Twitter should be indexable by content, relevancy, and date/time- and then users can decide what's best- like Google is doing now. And you should follow people on Twitter that make your life better- that make you think, laugh, understand things better- regardless of how many followers they have. If I enjoy twitpics of the Grand Canyon, I'll follow people that post them. If I enjoy celebrity updates, I'll follow people that give me celebrity updates. And if I want to follow people that Robert Scoble suggests will teach me something with every tweet, I'll follow them too.