This is a known and personally experienced issue (Tech Preview and Beta Builds as well) with Datasheet View not working in SharePoint if you have Office 2010×64 clients installed on your workstation.
Again this is one of the FAQ on the MSDN Forums and today I saw the solution posted on the thread, so comes this post for my reference and in case you experience this, then you know what is the solution to the issue.
Error Message: The list cannot be displayed in Datasheet View for one or more of the following reasons:
- A datasheet component compatible with Windows SharePoint Services is not installed.
- Your web browser does not support ActiveX controls.
- Support for ActiveX controls is disabled.
The workaround to this issue is to install 2007 Office System Driver: Data Connectivity Components post Office 2010×64 installation.
Very important to note ( information that you may not want to ignore)
The 2007 Office System Driver: Data Connectivity Components install a 32-bit version of the Datasheet component that will work with the 64-bit version of Office 2010 as long as you are using a 32-bit version of an Internet browser.
If you are using a 64-bit version of an Internet browser, for example the 64-bit version of Microsoft Internet Explorer 8.0, there is no support for the Edit in Datasheet component.
Also, you must install all 64-bit versions of Office products before you install the 2007 Office System Driver: Data Connectivity Components. Therefore, if you have to have Microsoft Project 2010, Microsoft Visio 2010, or Microsoft SharePoint Designer 2010 (These components are not installed as part of an Office 2010 suite), please install the 64-bit versions of these products before you install the Data Connectivity Components.