The next step, IMO, should be for Twitter to extend this to let third party websites and apps authenticate using Twitter's new protocol. Ultimately could be worth more than Twitter's core business. Essentially Facebook Connect done right, in a privacy-protecting way, with higher security.
do you remember only about 4 months ago a fake tweet on associated press twitter account about the whitehouse being bombed caused a stock market flash crash of nearly 1% which is over 100 billion dollars in the matter of 10 seconds or so???
thats why twitter HAS to provide robust security for the high credibility accounts or watch those accounts be closed down. anything else is great but thats the REAL driving force is to secure the 140 characters