Google reported the other day that their servers have now indexed over 1,000,000,000,000 URL's. Compare this with 26 million pages when they launched in 1998 and one billion in 2000. It's a pretty good estimate on how much the web has grown in the last 10 years.
I see no reason why this growth will slow down. Internet usage is still increasing in developing countries and every day millions of more pages are generated. It's amazing when you think the internet was originally used by academics to communicate with each other.