proper and out-of-the-box social capability
All most all CMS are now getting a "social" blend in the sense that they come with a social profile enabled or capability to do social networking. Will Silverstripe please,please quickly support an extension/module/plugin like http://buddypress.org ? This will essentially mean profile commenting+granular privacy+Social Apps/Gadgets+activity stream all integrated to one another.

easy and custom content types
How easily one can add own content types from the administrative interface?
Have a look at these
Wordpress - http://pods.uproot.us/ or Drupal - http://drupal.org/project/cck
A front end to manage and display the database query results for the same (like Drupal Views) would be not just cool but actually useful.

!deas
Please implement a section on this site for users' ideas like wordpress or http://ideas.mybboard.net/ or http://brainstorm.ubuntu.com

Have there been already feature requests for the above? If so, where can I join to add my voice ?
Thanks for this wonderful CMS.