These are the days of miracles and wonder.

Consider this: earlier this month, a black man was elected president of the United States.

And then there's this: around the same time, Seventh Generation, one of the most staunchly green companies on the planet, announced that it had launched a business partnership with Wal-Mart, long the company that greens most love to hate.

This was reality-defying news, along the lines of, say, Dennis Kucinich dating Sarah Palin. Seventh Generation had previously refused to do business with the Bentonville, Arkansas-based retailing giant. Now, out of nowhere, the lamb was laying down with the lion.

There must be something in the wind. Or water.

Jeff Hollender, Seventh Generation's CEO, has long been one of Wal-Mart's toughest critics. For him to have spearheaded this partnership says legions about how much Wal-Mart's  sustainability performance has improved—and about Hollender's evolving philosophy of engagement as well. "I've sometimes said that hell would freeze over before Seventh Generation would ever do business with Wal-Mart," he wrote recently. "In fact, at times I've made even more strongly worded statements. Now I've got to concede I was wrong."

The business relationship is still a modest one, and loaded on Seventh Generation's side with hedges (of the cautionary, not green, kind). Hollender takes pains to point out that it's a pilot project and a "very tentative partnership."

Also, Seventh Generation's household products won't be carried in Wal-Mart's superstores. Instead they'll be offered as part of a new retail concept, called Marketside, that Wal-Mart is rolling out in Arizona. The stores are small (10,000 to 12,000 square feet) and deliver fresh, ready-to-eat meals along with healthy products, making them a natural fit for Seventh Generation's eco-conscious buyers.

So what inspired Hollender to hop into bed with—or at least go out on a date with—the devil? Because the company is swapping out its cloven hooves for Birkenstocks.  "(I)t's an undeniable fact that Wal-Mart is changing in a very big way," Hollender acknowledges, citing the company's "audacious" environmental goals of being supplied by 100% renewable energy and producing zero waste as examples of its transformed commitment.

Since Wal-Mart has taken a giant step toward being more environmentally and socially responsible, it seemed only reasonable for Hollender to meet the company half-way. Which is precisely what has happened, down by the Marketside. "While there is much that is wrong with Wal-Mart," he writes, "it's also wrong for us to essentially boycott a retailer that is working hard to improve."

If there's a moral to this, it's that change really is in the air, and it's taking us away from partisanship and toward partnership. This is the signal promise of the Obama presidency (although it remains to be seen if it will deliver), and it's also apparent in Hollender's softened attitude.

Seventh Generation's CEO is very cognizant of the positive impact the 800-pound retailing gorilla would have if it successfully greens its own operations and those of its supply chain. "(W)e can't take on the world's challenges without Wal-Mart and its tens-of-thousands of partners and suppliers," he writes. "We now believe that we can have a bigger impact by partnering with Wal-Mart than by shunning it."