Today, Wizards of the Coast responded to questions regarding the terms of the new license submitted by posters at the popular Dungeons and Dragons fansite EN World. In short, the new license does not require companies wishing to publish under the new license to forgo open licensing. Instead, "Publishers will be able to decide on a product line by product line basis which license will work best for them." The full text of Wizards' response can be found in the linked thread.
It is unknown whether Wizards' position changed as a result of the furore that followed the events reported by mxyzplk, or whether the furore resulted from a misunderstanding of the license terms is unknown.