Encoding WAV16Bit 44100Hz to 24 or 32bit 48000Hz?

Hi i`m curious about this encoding type!I`m a aware that up-sampling digital audio can almost re-produce analogue accuracy, now this encode what effect will it have on the audio quality? and is it possible that this up-sampled audio can be burned to disc and retain it`s up-sampled sound on a standard Hi-Fi or does the sound system still require a up-sampling digital to analogue converter?

Ok now i want to know why Nero 7 reloaded would have such a up-sampled encoding type when a high end CD-player with up-sampling DAC will still be required?

Help will be appreciated and a comprehensive explanation would be highly welcomed...