Now that we are targeting Windows 7 and newer, we can get rid of references to the deprecated DXSDK_DIR location. All of the files and libraries previously shipped in older DXSDK distributions are part of the current Windows 7 (and newer) SDKs. Consequently, we should get rid of references to these outdated paths so that we can build with correct OS-level support.
I think this is largely moot, now that we generate builds from Make.