The new HomeOS paper entitled "The Home Needs an Operating System (and an App Store)" -- doesn't provide details as to what the base-level operating system would be. The researchers on HomeOS project have been doing field visits to homes with automation systems, and have come to some early conclusions.
HomeStore "inspired by the iPhone model," according to white paper would be a vehicle for simplifying distribution of apps and devices connected by HomeOS. It would also make recommendations and offer quality checks and ratings to users:
"HomeStore verifies compatibility between homes and apps. Based on users' desired tasks, it recommends apps that work in their homes. If a home doesn't have devices required for those tasks, it recommends appropriate devices as well. For instance, if a user wants integrated temperature and window control, HomeStore can recommend window controllers if there exists an app that combines those window controllers with user's existing thermostat. In addition, HomeStore can performbasic quality checks and support rating and reviewing to help identify poorly engineered apps and devices."
Interestingly, Microsoft isn't pushing for a single, Microsoft-controlled HomeStore.