Having said all of the above, let me hasten to add that I believe in the high likelihood of a coming singularity!
I believe in it because the alternatives are too awful to accept. Because, as we discussed before, the means of mass destruction, from A-bombs to germ warfare, are "democratizing" — spreading so rapidly among nations, groups, and individuals — that we had better see a rapid expansion in sanity and wisdom, or else we're all doomed.
Indeed, bucking the utterly prevalent cliché of cynicism, I suggest that strong evidence does indicate some cause for tentative optimism. An upward trend is already well in place. Overall levels of education, knowledge and sagacity in Western Civilization — and its constituent citizenry — have never been higher, and these levels may continue to improve, rapidly, in the coming century.
I just got Brin's The Transparent Society: Will Technology Force Us to Choose Between Privacy and Freedom? for Christmas, and have gotten about 40 pages into it. It looks really interesting so far. (I'm still finishing up I Have Landed: The End of a Beginning in Natural History by Stephen Jay Gould -- and for that matter I still have the last chapter of A New Kind of Science to wrap up too.)
If you want consistently insightful commentary, you should be reading Brin's blog regularly.