I once drove into Vegas on New Years eve and LVMPD was stopping every vehicle on I-15 southbound.I was carrying concealed and didn't have any problems. Ipersonally wouldn't hesitate to carry concealed anywhere in Las Vegas during New Yearseve. Of course I never drink and am always alert to my surroundings.
I also recently visited the Bellagio to look at the flower garden. They used to pop trunks before allowing entry, but this time I just got waved by.
I get the general feeling that security in Vegas is lightening up a little.