It seems crazy to think it could but there is a reason the Mac will be around forever, summed up in a few words by Wil Gomez:
Can iPhone replace a Mac? Yes. No. And, it depends. I’m thinking the old truck vs. car argument still reigns. The new iPhone may have a much larger selection of applications and more capability built-in, but for what many of us use Macs for these days, there isn’t a comparison.
Three words: Screen real estate.