Google: "We're Not Doing a Good Job with Structured Data" - ReadWriteWeb
http://www.readwriteweb.com/archives/google_were_not_doing_a_good_job_with_structured_data.php

That's something that's a bit troublesome - if better search technology for indexing the Deep Web comes into existence outside of Google, the world may not end up using it until such point Google either duplicates or acquires the invention.

Enabling a Google-like search from structured sources (databases)

Google and Yahoo approaching structued Web

Halevy, who heads the "Deep Web" search initiative at Google, described the "Shallow Web" as containing about 5 million web pages while the "Deep Web" is estimated to be 500 times the size. This hidden web is currently being indexed in part by Google's automated systems that submit queries to various databases, retrieving the content found for indexing. In addition to that aspect of the Deep Web - dubbed "vertical searching" - Halevy also referenced two other types of Deep Web Search: semantic search and product search.