Thou Microsoft has not directly come out with any product that integrates into the MS BI or its related stack of technologies, but 3rd party vendors have already started exploring the potential of visualization capability of Silverlight. Also to extend the reach of Silverlight content, Microsoft partnered with Novell and created Moonlight which is a plugin that can facilitate Linux users to access Silverlight content.
In June 2007, Dundas announced that it has licensed Microsoft for the usage of its source code for a part of Dundas Advanced Visualizations which included Dundas Charts and Dundas Gauge. And we saw a really professional set of charting and visualization capabilities in SSRS 2008. The first step in the share of Silverlight on the landscape of MS BI is on the delivery end of a BI solution i.e. Dashboarding and it has been developed by Dundas in the form of Dundas Dashboards developed using Silverlight. It's Dashboard visualizations are very impressive and in my viewpoint, it definitely has the potential to outperform the visualization capabilities of Performancepoint Server 2007. Thou Performancepoint Services for Sharepoint has now improvised in this area and seems like now it has digested the codebase of Proclarity to a better extent, but still in my views, the visualizations provided by Dundas Dashboards are quite competitive.