Jimmy, I don't think any NH (I don't know why it's a hemisphere thing considering the good teams are confined to Europe) will be a match for New Zealand, but England and Ireland have a fairly good record against SA, and I wouldn't discount France's chances either. SA even lost to Australia before the match here, so it's not like they're invincible.
Is that 'historically the two greatest teams' or are they claiming that the current two teams are the best that have ever played? There'd be an argument to make for New Zealand being the best ever, although I definitely wouldn't agree, but the current South African team are definitely not the second best that there's ever been. Even the SA team of 2009 is better than the current one.