Basically it's now $150 to change anything (i.e. can be a different flight between points on the same day). This takes away the flexibility of a Northwest RTW ticket from a traveller who wants to explore & enjoy the world. I wonder if NWA did this to match any other airlines' RTW programs?

To fly World Business Class around the world originating/finishing in the U.S. and buying with U.S. dollars, the cost is somewhere between $6000 and $7000. To fly W.B.C. around the world originating/finishing in Thailand and buying with Thai baht, the cost starts at approximately USD $3800 (not including tax) for the 25,000 mile level (that is, you have 25,000 miles with which to fly with), going to $4,100 + tax for the level I'm flying at (under 30K), to ~$4,750 for the 35K level. The maximum number of miles you can fly on a NWA R.T.W. ticket is 40,000.