Google says "Google Suggest To Become Default" service for, May be Learning From Cuil new search engine.
Google just announced they will start to roll out Google Suggest as a default feature for the homepage over the next week.
Google is convinced that it
1) helps formulate queries,
2) reduces spelling errors, and
3) saves keystrokes.

Check out see the Google Suggest FAQ.
The Google Suggest feature originally started as a 20% project in 2004, and has since expanded to Google Labs, Toolbar, Firefox search box, Maps and Web Search for select countries, the iPhone and BlackBerry, YouTube, and now