Crackers stroked a major blow to Microsoft anti-piracy efforts by releasing a BIOS SLIC based Windows 7 Activation Crack days before the official release of the software, while there are many other cracks and hacks like RemoveWAT used to pirate Windows 7 the BIOS SLIC hack allowed pirates to hide from Windows anti-piracy measures identifying itself as an OEM install.
According to a tweet by sp3ciali5t this is going to change with "Windows 8" as it will feature the next version of OEM Activation (OA 3.0).