The Sudan branches started investigating Linux a few years ago when XP was on the way out, the ribbon menu was introduced, and SIL lost their academic licensing status.
Similarly, today is again an ideal time to consider Linux for these reasons:
lots of time: You have 3 – 4 years of time to prepare before Windows 7 is gone. Microsoft’s appalling attitude shown in windows 8 development and windows 10 deployment prove that change will be a breath of fresh air.
Windows is seriously changing and is getting very Internet dependent.
SIL software should be mature on Linux: early adopters will have worked through the majority of the serious bugs.
You will not be alone. Within SIL, there is significant worldwide interest in Linux.
Web based workflows are reducing the dependency on specific OSs or office packages.
Budgets that were heavily squeezed recently are still very tight. Be partner friendly and use products that can be ethically distributed to any partner, and thus prevent licensing issues from being a barrier to working together.
So, prepare to dip your toes into the water when Wasta 16.04 is released in a few months.