What are the alternatives if I have Nero 8 already installed?
If you must have Nero 8 installed then you can use the libav decoder instead of Nero 7. By doing so, the AC3 & E-AC3 decoders might be at a small disadvantage quality-wise compared to Nero, but the difference is probably rather small. TrueHD decoding shouldn’t be a problem anyway, as eac3to uses the libav decoder as default decoder. Otherwise, for best AC3 & E-AC3 decoding today you still need Nero 7 with the Blu-ray/HD DVD plug-in.