Twitter is a free http://en.wikipedia.org/wiki/Social_networking and micro-blogging service...The Wikipedia definition is getting to be less accurate over time. It is getting clearer that Twitter is actually a “real-time short messaging service” or in other words a public pub/sub message broker. Obviously, one of Twitter's usages is social networking and micro-blogging service, same as http/html one of many usages is facilitating facebook communication. The messaging broker concept is rather old, though this time the producer and/or the consumer are typically human.
Twitter kills the RSS tools.
Since I've started using Twitter my typical use pattern is changing. At first I didn’t know what’s the big deal with sending short messages about what I’m doing right now, and why should one care. Actually, I still don’t get it. From using it for microblogging (“What are you doing?”), it starts to be a replacement for my RSS reader. Recently, we are seeing sites that recognized this trend appearing like mushrooms after rain. It is easier to filter out streams of Tweet news articles, sort items by timeline, and follow both high and low throughput sources. Twitter stream are sorted by time and everything there is streamlined together. Messages I personally post are mostly retweets of interesting tweets or items from other sources (like podcasts), and I use them mainly as a bookmark for myself.
Most of the news sources I follow already have a twitter feed. Twitter allows the news source to actually interact with the consumer; it is no longer a one-way communication. Soon, I assume, we’ll see retweets posted as talkbacks to articles on the article main site. I expect that there will be more similar companies providing services similar to Twitter, the protocol will be semi standard (similar to the RSS history), and it will be a major article syndication way. With clients like twhirl, which already support more then one provider, the message broker itself will be less relevant. It won’t be a surprise if some of the IT giants, like Google, will have similar service running.
Like Yammer for businesses, there are and will by companies that will try to provide added value on the server side. It does work, but the true innovation will come from the clients. Email for example, on the server side, didn’t change much in the last decade as a protocol and server software. Even gmail, a true innovation, is actually a client that happens to run as a web app. Same I assume will be with twitter, the interesting applications will be the ones that will produce and consume messages.