As has been publicized in many places, the beta for Windows 7 is available to the public, which is a first for Microsoft if I recall correctly. Product keys to activate the beta are available for the first 2.5 million people to download the software, which will expire on August 1. It has been made clear that the expiration date for the beta is not the official release date for Windows 7 (by then, there will be a new beta or perhaps even a release candidate).
I just ordered a new hard drive and will likely be giving this bad boy a test run. Vista gets railed on for a lot of things, so hopefully Microsoft has paid attention.