Looks pretty okay. Only couple of things:
X2 looks like a (weirdly shaped ;p) serial/bootloader program header, correct? In that case, it should NOT contain the reset but the DTR of the serial which is connected to the Arduino via a capacitor.
AREF should not connect to Vcc but to a cap to GND.
And yeah, crystal looks okay but I don't know many with >2 connections. But the diagram suggests it's connected to the casing which seems fine.
But in general I find it a lot easier to use an Arduino Pro Mini...