For decades, I've wondered about this too -- on its face it seems like an intriguing possibility, but deep down I think it was impossible. Reason: Extreme cultural mismatch. Not that they're so different, but because of their overlapping similarities. They would both have wanted to be on top, in the driver's seat, calling the shots. No way they would have gotten along. No mutual respect. Too many clashing egos. Especially during the Jobs years.
Oracle's acquisition of Sun was just sad, because they were wiping them out to make them go away, since Sun couldn't swallow their pride earlier and sell out to a company they considered themselves superior to, like IBM or Apple. So their window of opportunity closed, and they got scrapped and devoured by soulless vultures. An acqui-expire.
I would imagine some of the technology would remain, but all their current customers would have been jettisoned. I cannot imagine that the whole Illumos situation would have improved. I also think Java probably would have been dealt to IBM in that agreement a couple of years back.
Apple was not shy about telling NeXT customers to take a hike, and they are much bigger now.
Oracle's acquisition of Sun was just sad, because they were wiping them out to make them go away, since Sun couldn't swallow their pride earlier and sell out to a company they considered themselves superior to, like IBM or Apple. So their window of opportunity closed, and they got scrapped and devoured by soulless vultures. An acqui-expire.