It wasn't part of their 2010 April Fools thing; still seeing it today. First just the logo search box and standard / lucky buttons, then when you mouseover the page the top nav bar and more links under the search box.
Only once you've done a search and are in the results can you toggle for country-specific results; the default is web results.
Yes, I've been seeing it as the default in the Netherlands for about three days now. Not just Chrome but IE and FF as well. Because of the left nav bar, organic and right column adwords are even closer than before. There's also some changes to the search box styling and styling of sitelinks.
I was surfing and doing work when Google changed on me. It's got a new left column that pretty much duplicates the top bar but with more search filters. I don't like it. It gets in the way visually and it there are way too many customizable tools there. This is not the way I want to use Google. Keep it simple stupid.
[edited by: Robert_Charlton at 6:52 pm (utc) on Apr 4, 2010]
Saw new interface in Canada on April 1st, the whole day. Now it's gone. Not sure if this was the Jazz interface, but it was nice: bigger buttons, new skin on the buttons, bigger fonts. The SERP page was different too.
This is the "jazz" interface that Google is rolling out to more and more users.
Yes and it is garbage!
They put a cookie on your computer so you see the new design.... CLEARING COOKIES WORKS NICELY :) (I saw it for the first time yesterday and immediatly deleted thier cookie and got the good design back)