Where did the "All Users" folder from XP go in Windows 7?

C:\Users\Public\ is the equivalent to All Users in Win 7

Desktop is the folder you want (it is labelled Public Desktop) and it is hidden so you will need to set Show hidden files, folders, and drives

The full path is C:\Users\Public\Desktop (if your system drive is C:)

I know this has already been answered, and the answer is correct for most systems. However, sometimes the public folder does get moved elsewhere, particularly if you install Windows to a drive other than C:. You can use %allusersprofile% to always go to wherever the directory is installed on the given system.