Here’s another update which has one small improvement.
http://prerelease.componentone.com/hotfixes/winrtxaml/C1WinRTXAML_8.0.20133.36002_RC1.msi
Release Notes:
Release version 8.0.20133.36002 – 12/30/2013
C1.Xaml.PdfViewer
Improvements:
•Added support for JPEG 2000 format.