[we're doomed
Since J.G. seems like the probable choice for any Pink Floyd future surround mixes, I would only hope that things will only get better mix-wise in terms of future catalog 5.1 releases. Remember, we're talking about a great stereo engineer being asked to convert his way of thinking past two channels. The best thing for all of us who are so accustomed to listening in four channels and beyond would be to keep expectations low enough that any shining moments that may emerge will be unexpected and hopefully more recurring as time goes on.
The beauty is that since DSOTM 5.1 is already a done deal (like it or not), there won't be the same pressure on the next project to reproduce the mix that everybody has been overexposed to and couldn't possibly deviate from.
Once WYWH and TW are mixed in 5.1, (my guess as next in line), we can expect more adventurous mixes. If 5.1 makes it that far, Pink Floyd would certainly have had their mixing issues figured out by then. I have faith.