1. You should have the screen option to turn any number of content blocks on.
2. These content blocks are EXACT replica's of the main content block including media buttons and formatting. You should be able to interact with these content blocks in the same way as the main content block.
2. There should be radio button options and template tags so technical and non technical users can specify where they would like to use these in the theme ( pages AND posts ).
3. The content blocks MUST be completely readable by RSS feeds. This is where current plugins fail most urgently. For example - if you have text in one content block and images in another content block - both should be picked up by your feed.
Why? because fafing around with "more" tags is tedious and NOT USER FRIENDLY. There are plugins, but these do not do the job. WordPress has come on leaps and bounds with regards to becoming a fully functioning CMS. Changes like this would help it along even further.