The long-awaited Beta 2 build of Office 2007 is now available, as of 9:00AM PDT today. Get all the details here. It's a public beta, so anyone can sign up and download a copy.
For system requirements and Beta 2 installation tips, click here.
For developers, you'll also want to get the VSTO V3 CTP that works with Beta 2, which is also available as of today. Here's where to get it.
If you're doing development around the Office Open XML file formats, you'll want to install the February CTP of WinFX. Download it here.
If you're doing workflow development, be sure to install the latest Windows Workflow from WindowsWorkflow.net beta before you install Office 2007 Beta 2. Note that this build of WF is not compatible with the February CTP of WinFX.
And finally, if you'll be customizing MOSS 2007 (Microsoft Office Sharepoint Server 2007), you'll want to get the updated Windows Sharepoint Services V3 SDK. Click here for that one.
It's all free, so what are you waiting for? Download the bits today!