Could it be that you've unintentionally unchecked the Office Blue 2010 theme from the Themes listbox in the Upgrade Wizard? Our attempts to reproducing the problem yesterday were not successful: we got the theme we had included to the project checked automatically and only a manual uncheck made the Upgrade Wizard exclude the reference from the project.
the Telerik team
Q1’11 SP1 of RadControls for WinForms is available for download
; also available is the Q2'11 Roadmap
for Telerik Windows Forms controls.