I see the web page icon ('Favicon') has also changed, to a single multicoloured 'G'.
The new Icon certainly looks prominent and eye-caching, but to me it is so prominent as to be almost a little aggressive. Could this be a step back from the
'soft & cuddly' image that I thought Google generally tried to confer upon themselves?
Just my own subjective assessment mind, and no reason to think it will be typical of others.