RC1 will be distributed to 20,000 users already in the technical beta program, 500,000 MSDN and TechNet subscribers, and 1.5 million people who were in the Beta 2 Customer Preview Program (CPP), or public beta test. Microsoft intends to significantly widen the distribution by opening the door to new CPP testers. Information about the public beta test will be made available at a later time."
"In RC1, Microsoft has made numerous changes to the operating system. Of particular note is that the newly renamed Network and Sharing Center has been thoroughly redesigned, making it easier for users to perform tasks such as sharing files, folders and media or viewing a full map of the network and all of its devices."
"In addition, performance improvements have been made possible by fine-tuning I/O of background services. For example, Windows Defender is given lower I/O priority and so does not slow down performance of other applications, as it did during Beta 2."
"The UAC feature has been significantly streamlined and presents far fewer prompts. "
"For this release, Microsoft said it has substantially enlarged the driver pack to make it work better with a wider range of components and peripherals. The number of printer drivers in particular has been increased in RC1, and the new build also supports the Blu-ray and HD DVD high-definition DVD standards."
Also, .Net 3.0 is installed by default.
"Microsoft also said that the Windows Vista application programming interfaces are locked with RC1 and will not change. This means that developers can begin writing Windows Vista-specific applications and utilities, knowing that they will work on the shipping product.