Hey Adanac,
I have spoken with DJI in L.A. on two occasions and found out that they are going to be releasing the adapter plate for the F450/F550 shortly after the gimbal's release. I ordered an H3-3D from
http://www.bhphotovideo.com/c/product/1042174-REG/dji_zenmuse_h3_3d_3_axis_gimbal.html and was told after contacting customer service twice that their H3-3D version comes with the GCU & a adaptor plate for the Phantom 2. There was a bit of confusion on weather or not the Phantom 2 version came with a GCU, but they assured me that it did. If it doesn't, their gonna owe me one. I will know for sure on this coming Tuesday. If I cant retrofit the Phantom 2 adapter plate I will probably make my own. Have a good one. Eric