As quoted by Claburn in his post...
That's a lot of URLs. However, there's a lot of chaff in there. Consider that "Google" alone returns 2,740,000,000 Google search results, "Yahoo" returns 2,930,000,000, and "eBay" returns 1,080,000,000. Add up the number of results generated by searching for the top 100 keywords and you'd have a significant fraction of 1 trillion.
Wow! Google indexing is truly a leader in the market now.