Page remastered all of the CD's a few years ago, so I doubt they'll get anoher treatment.
The Led Zeppelin DVD sounds amazing, particularly the earliest show, with them at their simplist, and probably their best. It really sounds like you're right there.
The problem with hoping for better sounding mixes of their albums is that there just isn't much to work with. They were recorded rather cheaply, and I believe a lot of LZ II and III were recorded while they were on the road, in whatever studio they could find. I've even heard stories of songs being recorded in stairwells of venues they were playing in. I just don't think the source material is good enough to allow much improvement.
