i hate to be the spoil sport here, but that's not what the shirt says (i'm in my second year of studying arabic). maybe the picture has distorted the arabic script but it appears to say:

I [heart] [a collection of letters that phonetically looks like "s-brbk"].

to be "new york" there would have to be:
(1) a dot at the beginning (on the right) of the word on the second line
(2) a loopy thing right after the second "dip" as you move over to the left
(3) a second dot next to the one that is already there immediately to the left of #2
(4) another loopy thing just to the left of that
(5) replace the line with the single dot under it with a line that goes downward and curves to the left.

here's what it should look like (this one uses a different font, but this still basically shows what "new york should look like. note that there are a different number of dots and two loops which are missing from the t-shirt):

http://www.backspace.com/notes/2002/09/13/x.html

Thank you for the comment and the link!