Installed update 1 this morning. Thought it was pretty cool that it would allow me to "replace" the version rather than automatically make a new version, so I chose that.
Unfortunately, it seems that choice removed (and did not replace) libmmt.lib and at least libirc.lib -- not sure what else. (I searched after I got the linker error and it was not under the XE composer tree).
Fortunately, uninstalling and reinstalling Update 1 corrected the problem but thought you would like to know.