This was announced last year (jointly by AFKL/DL/VS): though DL was a few months slower than the others to implement, they had agreed with the other JV partners to start charging the change fee.

I would expect that ex-North America will continue to allow free changes (though with somewhat higher fares). The next big change is likely to be some form of Basic Delta One: AFKL in particular would like to introduce that (at this point, the only reason they haven't introduced it for flights to/from US/Canada is the Delta JV)... $500 to a $1000 extra for changeability, lounge access (unless Elite+), checked baggage (unless Elite+), and seat selection (unless Elite+) is probably the right ballpark for that.