It was easy to limit page editing only to the page owner in 1.5. I have the Role Manager plugin installed in WP 2.0, and I'm trying to figure out how to enable the edit_pages role in 2.0 for a user, but not allow that user the ability edit ALL pages. This functionality exists for edit posts (edit_others_posts), but what about pages?
I understand this isn't an issue with the plugin, rather this is a major shortcoming of WP 2.0, in terms of being able to use WordPress as a CMS. It doesn't seem like it would be a big deal to have create a capability "edit_others_pages" similar to edit_others_posts. This would allow user access control as needed when using WordPress 2.0 as a CMS.