I played around with the demo a bit, but it seems to be mostly geared towards shrinking a disk down to a single layer. I couldn't find a way to tell it "leave the video alone, but keep it in DVD format without spanish audio". It's either extract raw streams for editing, recompress, or convert for an iPod.

I did find this info on the Handbrake forums handy for automating a good chunk of the work on OS X.