[georgemcbay]

"As it stands today a Chrome user is no more valuable to Google than an IE user (well, apart from google being default search provider)"

I'm not sure your caveat is needed -- on a new installation the first thing Chrome does is ask you what search provider you want to use, you're just as free to pick Bing as Google.

[mistercow]

Chrome does this, but IE does not. That alone means that a much higher proportion of Chrome users will use Google than IE users. Then factor in the relative name recognition for the two search engines...