Yes, they are both supported. 

[X,Y] = meshgrid(mp(-2):mp(.2):mp(2), mp(-2):mp(.2):mp(2));

Z = X .* exp(-X.^2 - Y.^2);

surf(double(X),double(Y),double(Z))

However these functions are usually used for visualization and mp-arrays they produce should be converted to double for plotting (like above in surf function). 

Today we have added mp.randn to the toolbox (Windows). 

Linux & Mac OS X versions will be updated shortly.

Thank you for the suggestion.