Amongst some others, I've have been working on some of the articles in the New RDS Wiki on TechNet. Recently a new article came out by Pankaj Pande related on (non)visibility of RemoteApp programs in RD WebAccess.
"...In our previous blog entry on Remote Desktop Services resources for IT Pros, we mentioned that we'd added a new wiki for Remote Desktop Services in WS08 R2.This wiki has been growing quickly, thanks to the efforts of some of our community. Most recently, we've released a new article on the TechNet Wiki entitled The case of invisible RemoteApp programs (a.k.a. No RemoteApp programs listed on RD Web Access site). This article discusses one of the error messages that you may get while trying to add one or more RemoteApp sources by using the Configuration tab on the RD Web Access page. It includes an analysis and troubleshooting tips using RD Web Access Tracing. The article also covers the permissions related to WMI and DCOM that you can check when you get these error messages. If you have your own tips, we encourage you to add them to our wiki and link them to the appropriate landing page..."source: