So, the only thing needed would be adding {COT_AUTOFLD} to pages and anytime you add the extra field, it will be displayed there without further editing.

it would feature:
- a configuration: template to display extrafields (in Nemesis skin it would be something like <tr><td>Extrafield title></td><td>Extrafield value/field</td></tr>)
- extrafield whitelist/blacklist (if you don't want to have them all displayed)
- if needed: grouping extrafields in categories (and a template for such categories, in Nemesis it would be something like <tr><td colspan=2>Category name</td></tr>)

I already have some code for this plugin, I use a couple of solutions like this in my projects.

The only thing I want to ask is: what's the difference between Siena 0.9.11 and Siena 0.9.12 as for pages? I can do it easily for Siena 0.9.11, but in Siena 0.9.12 the page hooks were moved somewhere? Can anybody explain differences?