CTI Digital is currently building a super neat Design for a Omega subtheme that we are going to include in order to refer to it in our Handbooks and to simply give people something to look at for best practices.
The goal is to already be fully in line with the D8 CSS Coding Standards (http://drupal.org/node/1886770). While Omega 4.x core will do the heavy lifting of converting the existing D7 core CSS and templates to that standard (and override the corresponding template and CSS files from Core and some major contrib moduiles) we will build the CSS and templates specific to our demo/showcase theme according to those standards as well.
Additionally, our demo theme should be fully layout agnostic and play well with all the core layouts to come. Hence, the incorporated base styles should be fully generic.