Some of the startpost settings didn't work anymore, some required some tweaking and others were added in my version of the quality settings.
The current settings work best for me while multiboxing:

Low:
/console farclip 177
/console characterAmbient 0
/console skycloudlod 0
/console particleDensity 0.3
/console maxfps 20

Medium:
/console farclip 700
/console characterAmbient 1
/console skycloudlod 10
/console particleDensity 1
/console maxfps 30

High:
/console farclip 1000
/console characterAmbient 1
/console skycloudlod 10
/console particleDensity 1
/console maxfps 60


The far clipping was good already. The high quality settings could be 1000 or maybe higher.
The characterAmbient is now used correctly.
skycloudlod basically sets the cloud detail. I didn't notice much fps improvement in the cities, but I decided to add it anyway, because it might be pixel shader intensive (because of the bloom).
The particle density is set here too, but I didn't notice a big difference since I wasn't casting many spells. It probably offers a big difference when firing 5x fire nova totem or something similar.
maxpfs offers a big relief to your CPU and GPU. This will probably improve your computer's temperature. You might want to tweak this further, but 20 was good as a minimum, because there was no noticable 'shocking' behavior on the slaves(which is clearly visible at 15) and 30 is good as high quality setting, because your eyes probably won't notice much difference on an LCD when this value is set higher.

Here are some sample screenshots:
low quality
high quality
Notice the wolf's paws, the lighting on the charactes, the sky and the landscape geometry.

[edit] I have edited the related wiki page.