Not the equivalent. On Windows, when a program stops responding you can’t move the window and moving other windows over it causes its space to become a white square. That’s how Windows handles a program not responding, i.e., horribly. OS X gives you the spinning beach ball and still allows you to manipulate the program’s window because the program’s main thread isn’t tied to its responsiveness to the user interface.
Or you can do what 99% of users do and use task manager to close the non-responding program. But that wouldn’t make since when trying to make your point would it?
Also FWIW Vista and 7 doesn’t do what you described, at least not in the majority of programs I use that may stop responding or slowly respond. Firefox will often slowly respond when it opens a saved session and I am still able to simply minimize while it works it’s issues out, same thing with Yahoo. If for some reason My Computer stops responding or a folder has an issue then I can still open programs over the top of them, mostly without slowdown.