A screenshot of the first city, Markarth, is http://media1.gameinformer.com/imagefeed/screenshots/TheElderScrollsVSkyrim/TheElderScrollsVSkyrimMedia/Markarth01.jpg. Many of us have had hunches of what the 5 cities were with the map shown in the Todd Howard video but we couldn't see if there were any other cities. Now with this map, we no know that there are just the 5 massive cities with villages strewn around Skyrim.
As for Markarth, we don't know if there were just no NPCs around that part of the city at the time or they hadn't populated the city with NPCs yet (Not populated with NPCs for the screenshot seems more likely.)
Also it has come to my attention that Solitude is for the Empire and Windhelm is for the Rebels. These are the red words under the two cities names.