Cornel, You are doing the opposite of what I am doing. Instead of letting the compiler generate the code to read the XML configuration files, and then examining the variables, I am attempting to set the XML directly and configure BlazeDS that way, without using data files bound into the SWF. The following comment in the ServerConfig source code led me to believe that this should be possible: "The XML source is provided during the compilation process. However, there is currently no internal restriction preventing the acquisition of this XML data by other means, such as network, local file system, or shared object at runtime." (Second paragraph of http://opensource.adobe.com/svn/opensource/flex/sdk/trunk/frameworks/projects/rpc/src/mx/messaging/config/ServerConfig.as)
Here is a related bug: http://bugs.adobe.com/jira/browse/SDK-16073
