Yes, it appears that Xceed Software Inc. is making available for download their WPF grid control free of charge. The “gotcha” is that you have to register with your real name and valid work email address. Check it out at http://xceed.com/Grid_WPF_Intro.html.
For a list of features, visit http://xceed.com/Grid_WPF_Features.html.
There is also a demo for those with either Vista or IE browser and .NET 3.0 -- http://xceed.com/Grid_WPF_Demo.html.