I wouldn't count on Apple or any other manufacturer regarding this problem - it happened to the last 5 laptops I owned and no, I didn't dance on them 
The last one was a Macbook C2D and cleaning didn't help. Maybe the fact that some people have problems with it and other's don't can be accounted to tolerances in the manufacturing process. Plus it really takes a lot of time before the scratches become noticeable. I put my laptop in a messenger bag every morning and go to university by bike. I'm quite sure it took a few month before I saw them the first time.
I'll definitely buy a cover for my next computer. Maybe something which can be used to clean the screen as well. The scratches are not such a big deal, but they are in a place I look at quite often.
The last one was a Macbook C2D and cleaning didn't help. Maybe the fact that some people have problems with it and other's don't can be accounted to tolerances in the manufacturing process. Plus it really takes a lot of time before the scratches become noticeable. I put my laptop in a messenger bag every morning and go to university by bike. I'm quite sure it took a few month before I saw them the first time.
I'll definitely buy a cover for my next computer. Maybe something which can be used to clean the screen as well. The scratches are not such a big deal, but they are in a place I look at quite often.