I just finished reading Louis Gray's blog post about streaming versus conventional blogging, With the example of Steve Rubel's Posterous. Then had another look at Rubel's writings. Rubel conceives a situation where content producers might abandon traditional websites - the "hubs" of today's web - in favor of placing their content on services like Facebook (the "spokes", from which content emanates outward from blogs and websites).
Whether or not this proves to be true, I think that it requires no less writing acumen to produce an interesting stream than to author a traditional blog. Parts of Rubel's Posterous are quite boring, Successful streaming and microblogging require stylistic adjustments in order to create interesting content.