Does this look like dust?
Yes that's dust, hard to tell how bad it is, as that shot is going to make the dust stand out.
Shooting at tiny apertures (big f/ numbers) will make the dust show up much more. You unlikely to shoot at f/36 much in real life, so I doubt you'll see dust that bad in most pictures. If you see those dust bunnies in normal photography, then it's an issue. If you can't see them in normal pictures I wouldn't worry too much. When it becomes problematic for normal shots send it to Canon to have the sensor cleaned.