According to the terms of the EULA of the latest version of Safari for windows you will only be allowed to install it on an Apple-Labled Computer. This means if you aren’t a Dual Boot User, like those running Parallels or Boot Camp you can’t legally run the software.
This creates an interesting scenario for those of us who want to test that Safari renders our web pages correctly. It is unlikely that I will by a Mac specifically to test my web pages.
If this is an accident you’d expect Apple to swap the license pretty quickly. If it is intentional we may see interesting things in the future like iLife products that are only licensable for Apple Hardware Users, even though they run on the Windows Kernel.
Conversely it may set a precedent that PC Hardware Manufacturers may limit their software installs to machines with their own branding. Sony would seem a logical choice for such things. Sony branded PC’s seem to come with software that makes playing Blu-ray discs work better than similar hardware from Asus, and it would not be unthinkable to see Sony Lifestyle Software that is limited to Sony Labeled Hardware.