Sure, no one's saying Jobs will be forgotten to the sands of time any time soon. Yet 1000 years is a little bit of a stretch, especially when you try to size him up next to the ancient greats.
So you'd expect that someone who rises in the general consciousness now to actually be far more impactful than the 'ancient greats'.
This must be the first entrepreneur/capitalist/CEO that has been mourned on such a global scale, and that in itself is remarkable; there's no one who comes close. Maybe Warren Buffett, but outside of the US he's not that well-known. The only person I can think of from modern times might be Walt Disney, someone who was similarly creative, demanding, and left a cultural and commercial legacy behind.