Should ^^ (opPow) be left- or right-associative?

[KennyTM~]

Currently in D (r283) opPow is left-associative:

import std.stdio;
void main() {
        // prints 19683 instead of 7625597484987:
        writeln(3.0 ^^ 3.0 ^^ 3.0);
}

But the mathematical convention is a^b^c == a^(b^c).

Languages which the power operator is right-associative (3^3^3==7e12):
 - Python, Haskell, Ruby, Perl, Mathematica, Bash.

Languages which the power operator is left-associative (3^3^3==19683):
 - Octave/MATLAB, Excel, BASIC.