Disabling the login form is being considered as an option, but it is probably not going to be worked into the project list for awhile.
However, there is a shortcode that might accomplish what you are intending.
There is a status parameter for the [wp-members] shortcode to show content based on whether the user is logged in or out. And whether the page is blocked or not doesn't matter (although if it's blocked, the login form is going to show). The downside to using this method would be if you have a lot of content, applying it is not something that is automatic. But it would work.
The application of it would be as follows:
This is content that I don't care if everyone sees. It can be read by anyone.
[wp-members status="in"]This is content that can only be seen by logged in users. It will be blocked on any page or post.[/wp-members]
Hope that helps.