What can I use to get dust off of my rMBP display?
I recommend this $13 iKlear Screen Cleaning Bundle. 

It cleans dust and grime off of any modern screen (including iPhones and Macbooks) really well and I've been using it happily for the past few years. It comes with a chamois cloth and some special spray that cleans off dust very well without harming the screen (or you—it doesn't irritate skin in my experience).



Disclaimer: I am not affiliated with iKlear in any way.