I was at the pro store today and saw Slimshines on a permanent display, similar to the ones for the Lip Gelees. I also confirmed with the SA that they are now permanent.
Not sure if this has been mentioned somewhere else, but I thought some people would like to know
They've been permanent since the last repromote. New LE colours will come out with various collections, but the product itself is now a part of the regular MAC line.