Scriptorium, I understand what you are saying. So in this unique situation the Commemoration is only of the Feria Ember Wednesday. I suppose this would be true if it were an Office of 3 Lessons as well, were it to be possible? In other words, since their is a Collect for the Ember Day, no Commemoration will be made of the preceeding Sunday, is this correct for all Ember Days? Thanks.
If today were an Office of three Lessons, it would be of Ember Wednesday. Ferias of Advent and Lent are "greater non-privileged Ferias" and take precedence over Simple Feasts, so the Office would be of Ember Wednesday with a Commemoration of the Simple.
The preceding Sunday's Collect, as such, is not what is said - rather, it's the Collect of the current Feria, which is normally the same as the one for the Sunday. In other words, it's not said because the Sunday is commemorated (which it never is, except on the Sunday itself), but because the current Feria is. The Ember Days all have proper Collects, which are not, however, used at Vespers. (In the 1962 rubrics, the Collect for the Ember Day is used at all the Hours, including Vespers). So the Commemoration tonight will be Aurem tuam, and the same on Friday.