The only legit source that we can sanction here are releases from Microsoft. It has been distributed by Microsoft to some testers and also at conferences. Right now there are ways to get it online through the use of torrents, but these are not authorized copies. The evaluation builds are only good for 30 days right now and can be activated without a product key. There is no guarentee you will be able to upgrade to the final version upon its release. Release candidates can become available to you with a MSDN or TechNet subscription. You may also be lucky enough to qualify as a beta tester through Microsoft Connect when that becomes available. Any way you get it, I would strongly advise against using it on production computers. By this I...