So just a few days before this announcement, Mayor Bloomberg called the idea of congestion charging a "nonstarter" due to huge political opposition. On Earth Day, he proposed a three year pilot to charge cars $8 and trucks $21 for entering the busiest parts of Manhattan. By "busiest parts," he seems to mean everything below 86th street. Apparently any tolls on bridges and tunnels would be credited toward the daily charge.
I agree that it's probably a "nonstarter" due to political opposition not only in Albany but also in NYC. I for one think it is a great idea, and hope something comes of it.