Mine also has a lot of spots even after cleaning. I kept silent and avoided complaining until yesterday when I commented at someone's post on another forum and the fanboys jumped at me and started calling names such as troll, ignorant, unintelligent, etc... I haven't witnessed such behavior at Nikonians and this just shows the level of respect and education Nikonians have.
The camera itself is amazing and I couldn't be happier with everything about it but I mostly shoot landscape at small apertures so this is a real issue for me. I have another camera that has the famous/infamous sensor "bulb" issue, they replaced the sensor for me with a non-bulby one for free without even asking about warranty and receipt which I didn't have. Now that's what I call product support.