Four Corners no where it should be?

There is a lot of talk today that the Four Corners Monument (and the boundaries of Arizona, Utah, Colorado, and New Mexico) measurement is off by about 2 miles.  The truth is, no state is going to get land back because of this.  There is some argument that the prime meridian was not used, but another which would change the measurement.  

More realistically though, these boundaries have been set for over 100 years, so there's no way they are changing.