Nice tut, but I think if you're given a DTS audio source, you should convert it to WAV then straight to WMA.
Skip the AC3, which will further degrade the audio, by making 1 extra lossy conversion! Go from DTS to WAV then straight to WMA 10 Pro 5.1
Or, in the case for MP4 movies, go straight from DTS to AAC 2.0
If your plan is to encode the audio in WMA 10 pro 5.1, then converting WAV to AC3 is an unnecessary lossy step.
And if you plan to encode it into 2ch AAC LC, then again going to AC3 is pointless.
I understand the guides WMV and MP4 start with AC3 audio, and not DTS... but converting DTS to AC3 just to convert it again to WMA or AAC, seems a little weird.