There are probably quite a few magento forks out there, most notably mage+ comes to mind (http://www.mageplus.org). Should we support any of these forks or leave them out as they can deviate from the core platform?
I see no reason why not. The code is part of the Magento OSS ecosystem and questions will likely find a good home here. I see a likely benefit in exposing people to the architectural differences between the canonical version and any fork.