With NEX-6, how will Olympus respond? E-M6 and/or E-M5 price drop?

It's all about choice of quality lenses.

Quality prime lenses available for M4/3 system:
12mm f/2.0
17mm f/1.8 (rumored)
20mm f/1.7
25mm f/1.4
45mm f/1.8
75mm f/1.8

How many quality prime lenses does the NEX system have?

I think E-M5 is still very competitive with the 5 axis IBIS and the lens line up even without any price drop.