Audiograbber with Xing does that, doesn't it? If you switch off 'use intermediatery .wav file' then as it rips the audio from the CD it pipes it through to the MP3 encoder at the same time, so you get both the CD ripping and MP3 encoding progress bars increasing at the same rate.
You could argue that it is really being taken as a .wav format from the CD reader and then being piped in as .wav format data to the mp3 encoder, but it's close enough to direct ripping to mp3 for my dictionary.
Of course, all this is purely academic as nobody would actually *use* the Xing encoder...
A.