It basically has to do with a new definition of the geoid which is the reference datum used to define the earth's surface. It has to do with a new and more accurate definition of the earths surface which is continually being refined as a result of improved technology (also a new excuse to resurvey everything). Only surveyors and geodesists care about it.
GPS is not changing, it will continue to work as is. What is changing is the coordinate grid that some surveyors use.
Currently you can go into your hand held GPS receiver and change the datum to different datums such as NAD 27 CONUS, NAD 83, WGS 84 (which is typically the default), etc. You should always change the datum in your receiver to match the datum of a paper map if you are using it in conjunction with a paper map. For example, many of the older USGS topo maps are on NAD27 datum. If you try to plot coordinates on those maps using coordinates from your receiver that is set to WGS84 datum (and vice versa) you could be 200 or more meters off. That can be a significant problem.
This will just be a new datum, NAD22 and NAVD22 that surveyors will use.
WGS84 will continue to work, just as NAD 27 continues to work after NAD83 and WGS84 came along.
However, sometime in the future if you are working with a paper map that was drawn on the new NAD22 datum you could change the datum in your GPS receiver to match it if it's available in your receiver but as Fivers said you'll only be off a couple meters which is insignificant considering that you're only getting to within about 10 meters anyway.
I think your surveyor threw you a red herring Skook...
Mike Welling, WI Registered Land Surveyor 1840, MN Licensed Land Surveyor 26004
