They never will because that will impact their already slowing iPad sales and endanger their MBA/rMB sales.
I agree i hope they don't make a Mac tablet.
All Apple NEED to do is to improve and bring features like multi windows(split sceen) to IOS(hopefully for 9) for the Ipads then it be good.
Because if Apple don't bother making big updates to IOS for Ipads then i think they will be way less less demand for them especially since Windows 8 tablets like the Surface 3 are at a very price point compared to the Ipad.
What do you think?
But i do agree Apple should stick with IOS on there Ipads instead putting OSX on it.