We just verified today:
Our code signing script and instructions for signing FileMaker runtimes work for Mac OS X 10.10 Yosemite and Xcode 6.
For steps, please check old article:
Code Signing FileMaker Runtimes
So for the next time, we are save. Now just hope that FileMaker will continue to allow people to make runtimes in the next years.
The up to date script is included with our MBS FileMaker Plugin download.