Scroll along a bit further long that search bar.

I get:
http://www.google.com/m/search?client=ms-nokia-maemo&channel=unbox&q="Whatever I was searching"

Which delivers a standard view google page. At least, it does for me. Mind, I'm testing on wifi.. might it use google mobile (which is what you linked to) if it's on cell data? Must test!

The steps are: open 'web'. Click in the bar at the bottom and enter search terms. Click return and n900 will automatically run a google search on your terms.