David Anson is bringing the Silverlight Toolkit's TreeMap to WPF.
Now that Data Visualization is part of the Silverlight Toolkit and the WPF Toolkit, it has an official release vehicle for both platforms of interest. This is great because it means that any customers who need to be running signed bits from an official release have a place to get what they need. Of course, because the two Toolkits are not on the same ship schedule, there will probably always be a delta between them: some features or fixes that are present for one platform but not the other. Fortunately, the release cadence for the Toolkits is pretty short (on the order of months), so it won't take long for features to make their way into both releases.