The area is a major fishing ground for North Pacific fleets, including many crab, salmon, pollock and cod vessels that are based in Puget Sound. The bay also supports an abundance of wildlife, including major seabird populations and marine mammals that include the endangered North Pacific right whale.
The bay is a part of the Bering Sea, notorious for winter storms with high winds and high seas that could increase the risks of a major oil spill.
Ted Stevens thinks it's a good idea, as does Palin, but both have expressed a little worry about the fisheries and the usual platitudes about responsible development.
Given the oil industry's track record on spill cleanup and compensation (think Exxon, folks), I am VERY skeptical.