Recently, there have been a lot of discussions around the web about the "war" between Twitter and RSS subscriptions… about whether Twitter is killing the importance of RSS subscriptions. If you do a Google search with the keywords "Twitter killing rss", you will find a lot of information about this.
So why is Twitter brought to direct competition with RSS? Simply because you can get blog updates via Twitter. Now I am not going into a detailed theory about this; it has already been done.