According to the documentation, main() must be declared using one of the
following forms:

http://www.digitalmars.com/d/2.0/function.html
void main() { ... }
void main(char[][] args) { ... }
int main() { ... }
int main(char[][] args) { ... }

However with the latest D2 compiler I can write:
import std.stdio;

void main (string[] args) {
  writeln("main with string[]");
}

Actually I think that it is pretty good to be able to have main() with string[]. Bearophile on the forums even suggest:
In practice in D2 you can even use main(immutable string[] args), that I think is the best form