I might be resurrecting a thread that's better left in the past, but...
I came to this thread by searching for threads on the topic of "Focus-Follows-Mouse" or FFM. So, I thought I'd comment on this...
Here's something else you can do in Windows but can't do in OS X: Point to focus. It's the ability to switch windows without clicking on them, but merely by pointing to them with the mouse. This way, you can type, scroll, or otherwise fully use a window/program without bringing it into the foreground; the focus automatically follows your mouse. Sound cool? Yeah, it is. And it's something Windows users have had for ages. Unix users too. But apparently, there isn't a way to enable this in OS X. And that's a shame.
Okay, it's interesting that this is the opposite of my experience. So, I'm curious about your set-up.
The reason that I went looking on this topic was because I was so fed up with the lack of ANY kind of this behavior in Windows, especially around scrolling. I can't tell you how often I'm in a DB program and I've selected an element in a pop-up field, then I mouse over to the list that popped up and try to scroll the list using the scroll wheel, only to have my selection in the pop-up field changed because I didn't click my focus out of that field. This behavior drives me NUTS!
Now, to be fair, there are Windows apps that do let the scroll focus follow the mouse, such as Outlook, but it seems to be the exception, not the rule. Indeed, even in Outlook, if I mouse over an Explorer window that's in the background I cannot scroll it, let alone cause any keyboard input to go into it, without clicking on it to bring the focus to it.
Now, for my money, in general I don't want FFM. I've worked on Unix systems where it was set up, and I was forever accidentally pulling windows to the front because I had bumped the mouse, or tried to move it out of the way of where I was typing. It can be an extremely annoying thing. But scroll focus is definitely something different. I, for one, find that it is intuitive and logical that the scroll focus should be where the mouse is. After all, if you're scrolling (using the scroll wheel), then you're hand is on the mouse.
In any event, in my experience, Windows does not do this consistently, but OS X does. If I'm wrong, I'd love to know it.
In any event, while I freely grant that Windows does do some things better than OS X, OS X does do a much better job of maintaining consistency in UI throughout all applications. In general, the exceptions that I've found are usually (though not always) programs that have been ported from a Windows version without significantly changing the UI to match the Mac OS HIG.
Beyond that, they're both tools. Each has its strengths and weaknesses. Each is appropriate to be used in certain areas and not in others.