Hi Dave,
Thank you for your interest in Syncfusion products.
At present we do not support rendering PDF documents in the WinRT, however we do support rendering PDF document in the WF, WPF and MVC platforms. We have already logged a feature request report for the implementation of the PDF Viewer for WinRT. Please create a direct trac incident to follow up the implementation of the feature.
Please let us know if you have any concerns.
Thanks,
Suresh