Just use canned air, the macbook tilted and blow it out every so often. Keyboard covers tend to ... well make it less pretty, blur keys, and i find the lack of sliding my hands over the keyboard as well.
Also.. the new keyboards work slightly differently then the old ones. They depend less on the actual ability for a mechanism to touch something else as opposed to the sensing of the actual push... sorry i can't explain it correctly.
Anyway, as long as you take care of it and use some canned air every so often, dust will be legligible. Save the cover, and put it on when you think you may be in a really dusty environment (perhaps if you are outside with your comp on a nice day... or if you are like me and occasionaly go to the woodshop (product design major) and are going to be in a very dusty environment (ofcourse in that case I tend to cover the whole keyboard with something if I need it in there.
I am a neatfreak when it comes to my new computer, but I wipe it down with static cloths in an almost OCD like way and use canned air.
You'll be fine 🙂