Javascript is missing libraries. Even Lua has a very complete set of libraries, but Javascript has nothing, so it cant be used for general use programming.
Also I would like to see lexical scope added to Javascript so you dont have to put var in front of variables to make them local. Even Brenden admitted it was a mistake to leave out lexical scope and was just just following the mode of scripting languages at that time like Perl or TCL.
Someone should make a Coffeescript compiler instead of Coffeescript just being translater to Javascript.