I personally love the grainy feel, but enjoy it while it lasts because it'll become smooth and glossy after time
All you have to do to keep the grainy feel is not play with melted cheese before you use your laptop...
The grainy texture is supposed to be there, it makes it so you can slide your finger easily under most circumstances. I use an HP laptop at work, and its a flat smoothe surface that is impossible to slide my finger on smoothly. It jitters, sometimes I have to actually roll my finger to get any sort of accuracy.
I also noticed this, it bothers me somewhat but not enough for me to complain considering my macbook is otherwise perfect.
Anyone else notice this?