ISP - Wrong direction frying ATmega
No, connecting it backwards shouldn't do any damage, it just won't work.  The clue is in these two connections:

NC      -|-  GND
GND     -|-  NC


With it backwards the ground connection doesn't go anywhere.  Without that ground connection there's no circuit.  With no circuit, no current flows.

The only possible danger is to the protection diodes in the IO pins when you try and operate the programmer.  The lack of a ground connection could cause some current to flow the wrong way through the circuit (in through the ATMega's MISO pin and out through the MCU's Vcc pin) through the ESD protection diode.  That could cause damage to that diode and maybe the rest of the MISO pin's logic, but it's not that likely since the currents involved would be somewhat limited by the route the power then takes through the MISO pin of the programmer.