For those unfamiliar or who may be considering the Nikon 1 series, basically what the F-mount adapter does is that it should allow the use of standard DSLR lenses together with the new CX-format camera. So if you happen to have collected a series of lenses over the years but are looking to make the jump over to the mirrorless format, you will still have a ton of lenses to play with on a new body.
Unfortunately there will be some compromises to be made as attaching lenses to the F-mount will leave them restricted to the 2.7x crop factor. The F-mount adapter is expected to go on sale in Japan come 22nd of December for ¥23,310 (~$300) but no word on when they plan to make it available for the rest of the world.