  We note that there is an exception to the general arguments that no
falsifiable predictions can be made, on the basis of of presently available
data, by applying the weak anthropic principle (WAP) to the landscape of string
theory. If there are infinitely more vacua in the landscape for one sign of a
parameter than the other, within an anthropicaly allowed range, then under very
weak assumptions about the probability measure one gets a firm prediction
favoring that sign of that parameter. It is interesting to note that while the
understanding of the string landscape is evolving, present evidence on the
nature of the landscape allows such an argument to be made, leading to the
conclusion that the WAP favors a negative value for the cosmological constant,
$\Lambda$, in contradiction to the result of astronomical observations. The
viability of applying the WAP to string theory then requires that either there
are found an infinite discretum of anthropically allowed vacua for $\Lambda
>0$, or the recently found infinite discretum of solutions for $\Lambda <0$ be
reduced to a finite value.
