Being able to rip out parts of a DVD would be a grat feature, but since it is possible to do through other means (e.g., IFOEDIT) it's not a big deal.
What is a big deal would be to set different compression rates for titles. For example, when ripping American Graffiti, the whole move could be kept at 100% and still fit on the DVD with plenty of space to spare. The interview with George Lucas is almost as big as the movie itself. If I could compress the heck out of the extras and leave the move untouched (or very high), I'd be extremely grateful. DVD2ONE does such a SUPERB job at predicting the final file size, that I doubt this would be a big problem to implement.
In the meantime, does anyone know of a workaround?