Hi,
as I noticed, you transferred all non-core facilities to "plugin".
It's a very good idea: core should be stable for the whole release, unless for mantainance and debugging purposes, while plugins could be somehow customizable or interchangeble with others the comunity would develop (for free or for charge). The same for templates.
In order to achieve this goals, I think there should be full documentation on how to develop full functional plugins, templates and themes (read: Wordpress, Drupal, Prestashop): how did you think about this? The success of nopCommerce 2.0 (and the real reward of your efforts) rely prertty much on this.
Regards
Riccardo