Personally, I don't see too many people perceiving this guy to be white, regardless of how loose their interpretation. Even from the poor quality mug shots, he very obviously of Hispanic descent. Maybe other Hispanics and Hispanic mixes have a tilted view, but I'm pretty confident most people would describe him as Hispanic.
It's not an indicator of anything, but it has historically effected what stories the media chooses to push with a racism angle. How often do minority on minority crimes make national news in America with a decided racist spin? Not many, despite the fact that they're probably very common. Meanwhile it seems like there's a new white on minority piece almost every week. The point was this story probably gained most of it's traction on the (mistaken) assumption that Zimmerman was white. He's clearly not by most people's metric. This doesn't change anything about the case at all, but it does change how the media (and most people, see the first half of this thread) present it and perceive it. The fact that he apparently does have a history of doing the same thing to other people (not just blacks) is an indicator that perhaps this wasn't entirely racially motivated, or at least not to the degree as some would have liked.