Kevin,
I have the developer editions of both 10 and XI (11) on my primary development PC.
I had a need to use a dB that stored picures as a file path URL which CR XI can handle and CR 10 and SSRS cannot.
When I right click on a toolbar and click Add/Remove Items I have both version 10 and XI tools such as:
Report Class CrystalDecisions.CrystalReports.Engine 10.0.3300.0 and 11.0.3300.0
Report Document CrystalDecisions.CrystalReports.Engine 10.0.3300.0 and 11.0.3300.0
CrystalReportViewer CrystalDecisions.Windows.Forms 10.0.3300.0 and 11.0.3300.0
CrystalReportViewer CrystalDecisions.Web 10.0.3300.0 and 11.0.3300.0
MobileCrystalReportViewer CrystalDecisions.Web.Mobile 10.0.3300.0 and 11.0.3300.0

Best of Luck!