The concept of improved writing is interesting but misleading. I think computers and online activity tend to improve writing skills to a point. If you have children, you'll notice how any online activity results in them writing and spelling better so as not to look foolish in public. But all this does is move us from terrible writing skills to functional writing skills, and it seems to end right there. Many readers have pointed out that casual publication and a lack of online copy-editing have resulted in lots of bad writing on the Web.
Online regulars know it's okay to make a typo while online.
In fact, what gets posted on the Web is typically poorer in writing quality than what appears in print media, even newspapers. On the other hand, I think the Web will have a positive impact on reading and literacy and could perhaps help reverse the trend toward illiteracy. I don't see how this could be true any more than saying the Library of Congress has a mind of its own would be. Because the Web is on a network, I suppose using its widespread use could, in some odd way, have a neural net-like effect. But even this notion seems more like a piece of good fiction than reality.