As a Matlab person who recently switched over to Julia, below are some items on my wish list. Many thanks for your consideration!

Creating a m x n sized NaN should be as simple as NaN(m, n). Right now, I have to do this:
A = fill!(Array{Float64}(undef, m, n), NaN);

If I have two 1column data with the same size, A and B, I should be able to get an Index by
Ind = A>3 && B<15
. Right now, I would have to usemap
function to broadcast first:
Ind = map(A, B) do a, b
a>3 && b<15;
end

I should be able to initialize an array as
A=[]
, and then append to it as simple asA = [A; b];
Right now, Julia will complain that I can not append a 0 sized array with a m x n sized array. 
Automatically handle the conversion between vector and array for Index values, instead of relying on users to decide when to use
A
and when to usevec(A)
. 
Function should allow us to define the outcome of the function like:
function [A, B] = f1(x, y, z)
, instead of requiring us to usereturn
at the end of the function to return the results. 
I should be able to use a
sortrows
function, byB = sortrows(A, Index).
Instead of having to find the Index usingsortperm
first.