Microsoft has indicated in their blog that the next release of Windows 7 will not be a Beta 2 but a release candidate, indicating that they're pretty close and they want people to start testing the release, especially because all the features are done. All the folks running the Beta are actively contributing to fixing it. Theyre getting performance telemetry, application compatibility data, usage information, and details on device requirements among other areas. This data is very structured and very actionable. They have very high-bandwidth relationships with partners and good tools to help each other to deliver a great experience. One thing you might be seeing is that hardware and software vendors might be trying out updated drivers / software enhanced for Windows 7 - at least that is what they hope for.