If you're getting everything into place to be able to download Office 2010 in the coming weeks, then you hopefully know that you need to use KMS for activation. If you previously had this setup for the Office 2010 Beta version, you would've downloaded an Office 2010 KMS Host License Pack (BETA).

You WILL need to upgrade this component to be able to install your RTM Office 2010 KMS keys which are already available from the Volume Licensing website.

if you try and run the beta version of the Office 2010 Host License Pack and install an RTM office 2010 KMS key you will get this error:

An error ccurred: 0xC004F050

The Software Licensing Service reported that the product key is invalid.
Re-run and enter a valid Microsoft office 2010 KMS host product key.

The RTM version of the Host License Pack can be found here:

Download details: Office 2010 KMS Host License Pack
http://www.microsoft.com/downloads/details.aspx?displaylang=en&FamilyID=97b7b710-6831-4ce5-9ff5-fdc21fe8d965

EDIT (13th May 2010): So, one gotcha I've recently become aware of is that the KMS Host for Office 2010 will not work on Windows Server 2008! It will only work on Windows Server 2008 R2, Windows Server 2003 and Windows 7. WTF?

References:

Microsoft Office 2010 Engineering : Volume Activation
http://blogs.technet.com/office2010/archive/2009/08/24/volume-activation.aspx

Why no support for Server 2008 (non R2)
http://social.technet.microsoft.com/Forums/en-US/officevolact/thread/8b05513a-92f0-48b9-936c-de6b89b09ff1

So, in short, if you are planning your KMS infrastructure (or just/recently deployed), it is highly recommended you move it to a Windows Server 2008 R2 host to 'future-proof' it... well... for the forseeable future anyway :)