ACP/MCP = No plugins for 3.5.
I would look for those in a later release, but they have not said anything about whether it is under consideration -- only that they are looking to combine the ACP and MCP. I would *assume* that plugins would be addressed as many modifications have ACP mods as part of their install.
I too would like to see it as default, but I added this the first month I rolled out subscriptions and I am not going back to not having it while waiting to see.