I don't know if anyone else heard this at their interview, but they told the first two weeks of interviewees that in 2-3 weeks they would either tell them "yes" or "we're still thinking about it" after comparing to the first few pools of interviews. They also said that when they say they're still thinking about it, they "really are still thinking about it." So I don't think it's essentially a rejection... I haven't heard anything so I'm guessing I have one of those letters when I get home today...
Pretty sure I have one of those letters waiting at home too. I do also remember them telling us that it isn't a rejection. Still a major bummer though.