What a lot of people seem to miss is that Xcode 4 is still a free download on http://developer.apple.com/xcode/ for members of the developer program (which is a free membership).
"for members of the developer program (which is a free membership)."
no, it's only free for members of the paid developer program.
free members who try and download it are given a link to the appstore or an option to purchase the yearly membership.