I currently have Sins of a Solar Empire & Demigod retail with Entrenchment on digital and when checking under my products on the Stardock store all are listed as requiring Impulse even my retail purchases.
I am fairly certain that you will have full access to these when StarDock Central becomes available to the public for downloads, patches and re-installs.
So SDC will be their new (old again?) way to update/re-install retail and Stardock store sold games or all games including those sold via other digital distribution vendors?
My biggest concern is that my retail Stardock games don't end up being tied forever to a vendor I really don't want to use.