In case no one noticed, I’m a fan of the ReportViewer control. While it’s not free like SQL Express (you have to actually pay for one of the non-Express versions of Visual Studio to get it), it does give developers a way to design, tune, test and deploy reports along with their applications—either ASP.NET or Windows Forms—without Reporting Services. And no, the control is not included the WPF toolbox. IMHO, this is a major oversight. Yes, yes, the WPF folks are busy making the interface as similar to Windows Forms or ASP as they can, but it seems to me that they should also make sure that some of the newer (and more important) controls are implemented.
However, in my opinion, that’s not the biggest oversight. It seems that the new version of the ReportViewer control (now renamed “MicrosoftReportViewer” control because there’s also now a 
“CrystalReportViewer” control), is not really all that new. When Microsoft’s Reporting Services team got inundated with comments, gripes and over-ripe tomatoes from RS developers, they (wisely) chose to reengineer the report processor. This required some significant changes in the “language” the report processor interprets—the RDL. This “2nd generation” RDL supports the new Tablix control, rich text and lots of other features. The newly release Visual Studio 2005 SP1 BI tools shows off this functionality and dutifully creates 2nd generation RDL. The problem is, the ReportViewer control that’s shipped in Visual Studio 2008 is roughly the same as the one in 2005 and it does not include the updated report processor. This means it can’t process 2nd generation RDL.
This also means that the reports you build with the VS BI tools cannot be imported into VS 2008 ReportViewer projects. This is not scheduled to be fixed until Visual Studio 2010.
If you think this is an issue, I encourage you to go to Microsoft Connect and vote on the bug I have raised there to try to get Microsoft to fix this before VS 2010. See https://connect.microsoft.com/VisualStudio/feedback/ViewFeedback.aspx?FeedbackID=380814
