What I'm seeing is that the options start fading in as soon as you move your cursor anywhere inside your browser window. It's probably a one-second or so fade-in, once the cursor moves.
If you don't touch the mouse, the options don't fade in at all... at least on IE8 and Firefox. I've let things sit for well over a minute, and nothing happened. There was no fade-in. I don't think it's browser specific.
Are they trying to train the public only to use the search box?
Selective fade-ins are a graphic design device that you'll see used a lot in movies and TV commercials, particularly in titles, but often in dissolves, to draw your eye first to what appears first, and then to what changes... as opposed, ie, to both at once.
IMO, Google is trying to say:
"See, our main emphasis is on the search box, and here are a bunch of other options too." For some, this is creating a usability issue. You can type in the search box and press Enter, and... if you haven't moved your mouse during this process... you will be taken to the serps without ever having seen the options on the Google home page. From a designer's point of view, I can see arguments on both sides of this particular behavior... I mean, why distract users with a fade-in while they're typing?
I can also see arguments against the fade-in at all.
You might say, though, that the fade-in has done what it's been intended to do, which is to call attention to both the search box and the options. My guess is that this is just one more test on a variation of this approach.
