Quoting Simon Swegles simon@swegles.com:
Is there a way to set nodeaccess grants to be default for a particular node type? I have a situation in which I want users to be able to create content, and then only the creating user and a particular group will have access to the content. Nodeaccess pretty much fits the bill, but the grants are only made available globally, rather than being actually set.
I've seen this discussed before. There is currently no method to control the access to the content at the node level within the Drupal core. I haven't researched on what might be possible but nodeaccess would have to be able to hook into the access control features and provide new methods to control the content viewing at the node level. I don't know if that is currently doable. I don't think it is being considered for drupal 6 either (see: http://drupal.org/drupal-6-status-update) so maybe it can be suggested for version 7.
Earnie