Due to a total revamp of Moodle Docs some existing Moodle 1.9 Theme and FAQ pages have been duplicated and place in another area and labeled Moodle 2.0 and are in the process of being updated. So if you have looked for some guidance to help you learn more about Moodle 2.0 themes, and found these older Moodle Docs labeled 2.0 then you will have been sadly disappointed and led down the wrong path. So apologies for this.
I'm trying to regain some semblance of order in the chaos so if you find some Moodle Docs labeled as Moodle 2.0 but in the text refer to Moodle 1.9 please leave a link to that page in this thread and I'll go and Edit it.
Many thanks for your co-operation in this.