The debate, for the moment, seems to have ended in favor of the latter camp, as Potion Sickness has disappeared from the Beta servers in the latest build. As of this writing, there is no word on whether the removal was intended, and if so, whether or not Blizzard intends to return it or a similar mechanic to the Beta servers at a later date.
For now, though, it looks like chain chugging is back. As a member of the former of the aforementioned camps, I'm a bit concerned, and I hope they continue to work on limiting chain chugging. Farming for potions as a mandatory part of 10 or 25-man raiding really isn't fun and doesn't, in my mind, add much value to the encounters, and I'd much rather see a limitation of potion use combined with class buffs and boss balancing to remove the need to chug altogether.
In other profession news, Herbalists got their own version of the buffs recently given to Skinners and Miners in the form of Wild Growth, which heals you for an amount of health over 5 seconds. The healing amount (2000 at the highest rank) does not appear to be affected by spell power, nor does it scale with HP in any noticeable way, so that may make it a bit weak as HP pools grow. However, it does not appear to share a cool down with other healing abilities, and it is usable in Feral forms, so it still may have a bit of utility after all if you can spare the global cooldown.