I can understand the drive to download the rules early and check them out. Truth be told, there was a time not long ago when I might have considered doing the same thing. But as it stands, I voted to not download but definitely read the spoilers. At this point, I'm okay with waiting the two more months for my pre-ordered books to ship out in hard cover. I'm interested enough in 4E to get the little tidbits, but not driven to know it all at this point.
Now, on the realistic side, I doubt anything like that is going to happen, simply because I'm sure WOTC is being pretty tight with the 4E content. After all, part of the problem with the GSL release is likely someone's fear of exactly this kind of thing happening (not the entire problem, mind you, but it could be a contributing factor). But even if it did, I wouldn't download the files. I just don't have the drive to know that I used to with 3E.
YMMV, Of Course,
Flynn