Intel C vs Intel Fortran : http://shootout.alioth.debian.org/gp4/benchmark.php?test=all...
(I'm not even going to link to the GCC Fortran benchmarks. They're embarrassing.)
C is no slower than Fortran on any of those benchmarks, and on some it cleans Fortran's clock. The aliasing issue is the only thing Fortran has going in its favor, but clearly its not ubiquitous. The n-body benchmark, for instance, is fairly typical numerical code. You might even think, since it's simultaneously reading and writing through multiple pointers of the same type, that aliasing is an issue, but its not. And in the rare case that it becomes an issue, there's compiler hints (e.g. C99 restrict) for that.
Picking Fortran over C solely because of aliasing worries is premature optimization of the worst kind.