Also, do note that P5000 can give you a longer zoom using the teleconverter which the GX100 lacks and that you can use Nikon's fantastic flashes on the P5000 and your future (Nikon) DSLRs.
For me, I bought the GX100 as it comes with built-in wide-angle (24mm!) and can write RAW.
vans_cafe, you bought the GX100 yet?