Ah, I had assumed that the 448k bit-rate was on a per-channel basis, thus it would be the same with 2.0 vs 5.1 (just with less channels). But *if* 448k is the total combined bit-rate for all channels of a DD 5.1 soundtrack, then I agree that it's not necessary for a 2.0 soundtrack, although it would be nice.

If there were only one 2.0 soundtrack being included and nothing else, then I'd say you might as well crank it to 448k and go for max quality, since there's room to spare, but since this DVD will include a few soundtrack options, then space might be an issue. Bear in mind that when this is played on a quality home theater system (as many Star Wars fans will no doubt do), you really want a hi-fi soundtrack, as compression artifacts/limitations become noticeable on transparent audio systems, it makes the soundtrack sound tinny. Also, since these PCM soundtracks are so nice to begin with, you want to capture and preserve that great quality. So I think it's best to aim for the high end of that and go with 320k for the 2.0 soundtracks. Unless, what with the other included soundtracks, it absolutely will not fit on a dual-layer DVD disk. In which case, go for 256k.