I might do that down the road.  The 902 has a 120mm side intake fan blowing directly onto the two cards and there are two 120mm intake fans in the front.  The top and back case fans are exhausting air out the back.  Plus the power supply on the bottom is also exhausting.  Temps are fine for everything even when running P95 and Furmark at the same time. 
 
My only concern right now is the Vreg.  While running p95 and Furmark at the same time the vreg will hit the mid 70s.  I know that is still safe but I plan on installing a small fan for it mainly to lower the idle temps.  After that I will see if anymore cooling is necessary as I start overclocking.  I don't plan on overclocking much at this point.  I will need to invest in a more powerful power supply if I overclock too much.  I am already drawing @650 watts from the outlet while running Furmark and P95 at the same time.  That equates to @520 watts at 80% effeciency that the pc is using.  My power supply is only rated for 620 watts so I don't want to push it too much further.  I can hear slight noises coming from the power supply when running P95 and Furmark together.  I know that nothing will push the pc to that level of stress under normal use but it is a good way to test 100% stability.