The folks over at Mixware debuted a clear tough flexible plastic cover at Winter NAMM 2014 for the StudioLive 1642 mixer.
Looks like it might be a great idea for mixing with overcast skies or where liquid might get spilled but you still need to see what your mixer is doing.
They just notified us that these are now available. Contact Mixware for where you can get one.
More info on it can be found at: http://mixware.net/product_detail.php?product=DSP-PC-SL1642