Walmart: Supporting local farms & regional economies?

Walmart, the world's largest retailer, is probably best known for its history of effectively crippling local economies. So, its announcement to support the sustainable, local food movement comes as a huge surprise. The first three articles I read online had me literally scoffing out loud. But, given the sheer size of the corporation, any positive changes it makes could lead to widespread results. The question is, will all of the results be positive?
Here are some of the changes that Walmart has proposed:

• Walmart plans to double the amount of locally grown produce it sells by the end of 2015 (reaching  a level of 9% in US stores)
• They plan to sell $1 billion in food produced by 1 million small and medium sized farmers by the end of 2015
• They expect to raise the income of local farmers by 10-15% 
• They have promised to provide training to 1 million farmers and farm workers, providing education in areas such as crop rotation and sustainable practices (they estimate 50% of those educated will be women)
• They plan to encourage the production of more food using fewers resources, while producing less waste (why doesn't this practice apply to ALL farmers they purchase from, local or not?)
• Walmart says they will now ask suppliers about the water, energy, fertilizer and pesticide use per unit of food (but will they supply those details to consumers?)
• They also plan to focus on the two major contributors to global deforestation: palm oil and beef production (promising to purchase & use products from those who use sustainable practices)
• Even more ambitious are the numbers for Canada - Walmart plans to boost local food numbers to 30% by the end of 2013
• Walmart hopes to encourage local farmers to return to growing fruits and vegetables that used to grow in that region, ie. more heritage varieties ( How will the-lord-over-all-that-grows, Monsanto, feel about these *coff* heritage seeds?)

The questions this announcement doesn't address is whether or not the use of GM foods will be allowed and whether or not customers will be privy to the information collected by Walmart. It's all well and good to say that you are going to ask someone about their practices. It's another thing altogether to act responsibly on those answers. I'd really like to know what Walmart considers sustainable and whether or not an annual income increase of 10-15% is really considered enough. What kind of hidden costs are involved in signing a contract of this magnitude with Walmart? And, what will Monsanto have to say about the use of 'heritage' seeds? Call me skeptical, but their plans sound too good to be true.
Even though I'll still never shop at Walmart, I'm giving them half a thumb up for effort. Any change affected by such a huge corporation is bound to go far. There are plenty of people who shop regularly at Walmart so there is huge potential for good here... but, if you're anything like me you're thinking "What's the catch?"

Your thoughts?