Don't really watch DSTV that much anymore, but I really can't see what the fuss is with the numbers changing? The UK did this some time back with SKY.
As mentioned by others, channels are running out. Its just easier to get people to use a 3 number system, and also learn the numbered genres (eg 200-250 for sport) (before 20-33). Give it 3 days and you should know the new system???
Yes DSTV doesn't have the best range of services (and its expensive), but its still far better than the alternative (20 year old movies filled with hours of ads on ETV, not to mention SABC!).
Hopefully this move means they're slightly scared of the upcoming competition and that the service will only get better with new channels and/or cheaper packages (one can dream

)