Sign in with a Windows Live ID and say that you're an IT Worker and you can download it.
'Beyond the obvious bug fixes and security patches, we'll no doubt see support for the new USB 3.0 standard. Likewise, enhancements to the Bluetooth and Wi-Fi stacks will be slipstreamed in, allowing Windows 7 to retain its mantle as the most easily configured version ever,' writes InfoWorld's Randall Kennedy. 'But perhaps the most significant "update" to come out of Service Pack 1 will be the fact that it exists at all, and that by delivering it to market Microsoft will be signaling that it is now OK for IT shops to pull the trigger on their Windows 7 deployments.'"
I can really tell that there are improvements to the wi-fi as I'm getting consistently higher bars with better speeds.
This is a beta so non-tech-savvy people should use at their own discretion.