According to this article Walmart will be making all its suppliers reveal their environmental performance through a Green Ratings system.
Walmart has been taking the lead on many green initiatives in the past several years, sending shock waves up and down their massive supply chain. This new initiative will impact their 100,000+ suppliers.
Personally, I'm looking forward to the new rating system. I do hope it will bring some clarity to the eco-footprint questions I have when I stand in front of a shelf of different brands. The labeling will certainly make shopping at Walmart a more transparent experience.