I assume that's because I was the 3839th person to sign up for an account on Twitter. If you have a Twitter account you have a feed. If you want to find it, you can use the Twitter RSS bookmarklet.
Personally, I don't subscribe to anyone's Twitter feed in my RSS aggregator, and I'm a systematic user of RSS (of course). Twitter feeds are not generally news-heavy, and that's the primary reason I use RSS. Adam Curry tried an experiment and subscribed to all the Twitter users he follows in Blork and wrote up the experience.
2. On the other side, much of the news you get in Twitter flows through TwitterFeed from RSS and Atom feeds. You can check that out, I have. If you're seeing news in Twitter, it's very likely coming from RSS.