In an Ubuntu Developer Summit session today, Matthieu James (Graphic/Visual Designer at Canonical) presented the design guidelines as well as some of the work done to create a new icon theme for Ubuntu (both desktop and touch).

The main goal is to finalize the new icon theme for 14.04 on touch devices but it's also possible for the icon theme to be available for Ubuntu 14.04 Trusty Tahr on the desktop.

Here are a few screenshots with some of the slides in Matthieu's presentation (the quality is pretty bad since I took screenshots of the G+ hangout):

Unfortunately, the presentation used in the vUDS session is not yet available, but you can watch the entire session below: