This is the DL reaction to SAA joining STAR- they told SAA of their intentions the day after the official announcement SAA made re STAR. Delta seem to have taken the whole STAR thing very personally with lots of petty "reprisals" like quadrupling SAA handling charges at JFK and ATL overnight, increasing the price (doubling) they charge SAA for add-ons to other US cities. Whilst I understand their feelings the way in which they have conducted themselves is more akin pouty teenagers. Its just business guys.
Word is that ORD will come on line later this year as SAA needs the connectivity UA has over this gateway- then its going to be an interesting to see who gets more traffic over their respective hub. Bearing in mind SAA also operates into JFK and IAD and with Delta only operating a B767, SAA will have a lot more capacity into the US. I guess it will all boil down to who has better feed at the best price. Time will tell.