You can already register yourself as node provider, see https://wiki.internetcomputer.org/wiki/Node_Provider_Onboarding. Making it easier to become a node provider is being worked on and you can follow the progress here The State and Direction of Decentralization & Nodes on the Internet Computer.
Wrt making blocks publicly available, there is a forum discussion Discussion: public subnets, but there isn’t clear agreement yet on this topic.