Julia looks very promising for fast and syntax-sane computation (e.g. here), but I suspect it will not be anywhere near R in terms of overall statistics workflow for some ti
The Julia development plan, as I described in this answer is to allow compilation of Julia code to shared libraries, callable using the C ABI. Once this happens, it will be as easy to call Julia code from R as it is to call C/C++ code. There is, however, a fair amount of work required before this becomes possible.