Thanks for the feedback! I have personally heard this request from a number of customers. IMHO having the ability to use GMS accounts would be a quite useful in DSC configurations. If this is an important feature for you as well, vote it up so that we can appropriately prioritize it as we move forward.
An error occurred while saving the commentgaelcolas commented
I'd add that Open Sourcing the PSDesiredStateConfiguration.psm1 would be a great enabler to add such features.