I have been reading the posts on cuill which claims to index three times as large as Google's - searching for results across 120 billion web pages compared with Google's index of 40 billion pages but i find it ordinary , i have just done few test on for both search engines and i can say cuill needs lot of improvement in terms of UI and relevancy.

I agree with richrad that Having ex-Googlers at the helm and making big claims is nothing new. They were also coming out of stealth mode, which helped the PR. But perhaps what made the difference this time was that some key industry pundits made some big claims themselves about Cuil.

Danny Sullivan, who runs SearchEngineLand and is generally considered to be the most respected search blogger around, is quoted in the NYT as saying: "This is the most promising thing I've seen in a while". He did qualify that by saying: "Whether they are going to threaten Microsoft, much less Google, that's another story." And his own post on SEL goes deep into this very question - well worth reading.