Looks technical, and one for the more geekish amongst us, but here's the paragraph to pay attention to:
"With access to Twitter’s history, businesses could learn how consumer sentiment has changed over time or what people have been saying worldwide about their products and services for more than a decade, for example. But it could also allow for new tools to surface historical tweets in an easier fashion than Twitter’s own advanced search features do today."
For more detail, visit TechCrunch.