A lot of people clamoring for a truly pro iPad (aka Mac slate) from Apple. I just want to write my thoughts on why I really don't think it's going to happen any time within the next several years. For a Mac slate, the issue isn't hardware. Hardware-wise, all Apple has to do is create something similar to the MS Surface Pro 3, which I think has the hardware as close to perfect as can be expected. So that answer already exists. It's software that's the problem. A pro touch tablet needs an ecosystem of pro touch applications, not an ecosystem of dumbed-down iOS apps, and not an ecosystem of touch-unfriendly OSX applications, which is all we have at the moment. Somehow getting developers to redesign all the thousands and thousands of existing OSX applications so that the interfaces can switch between touch and non-touch depending on which device it's running on, seems almost impossible for even Apple to do. And building an entirely new ecosystem of desktop-level applications designed for touch seems even more improbable. Perhaps the demand for such applications is growing now that the multitudes have become accustomed to and fond of touch interfaces on phones and tablets, and are possibly starting to want the same experience "ported" over to their computers. If the demand grows enough, a true pro Apple tablet and an ecosystem of pro touch applications will come to pass by necessity. But I don't think it's close to that point yet.
Side note - Touch tablet use is more about preference for the majority, but who this situation really sucks for is those who need pen input on Mac applications on an ultraportable device (note-takers, composers, artists). Right now, they have to either use neutered mobile apps, or stay chained to a desk with their Macs and Cintiqs. Or switch to Windows... -_-
Apple could create a hybrid iOS-OSX device (like the SP3) in the meantime if they thought it worthwhile, but obviously they haven't so far, and I don't think they will any time soon for two reasons:
1) Out of principle they probably believe a smaller, lighter iPad is a better experience for casual consumption than a large 12" 1.75 lb. tablet; and a light and sturdy clamshell laptop with a nice keyboard and trackpad is a better experience for desktop applications than a subpar keyboard/trackpad cover which flaps around and has to be used with a kickstand on larger and flatter surfaces; and those advantages collectively outweigh the advantages of a hybrid, which are that you save about half a pound of weight in your bag (when including the keyboard cover), and you save probably a few hundred dollars.
1b) Apple probably wants to keep those few hundred dollars.
2) I'm not a tech expert, but from what I've read, the problem is the type of processors iOS apps and OSX applications run on. iOS apps run on ARM processors and OSX applications run on x86 processors and they are incompatible. So I'm led to assume that in order to make a hybrid device that runs both app ecosystems, Apple would need to include both processors in the device. That's kinda nuts. I'm not aware of any devices--especially mobile devices which need to stay thin and light--that have two different kinds of processors. I imagine implementing two processors would create an overly-complex and therefore bulkier-than-normal tablet, which would put it at a disadvantage to the SP3 right out of the gate. Not to mention, I'm pretty sure having a different processor for each set of apps also means the device would have to be rebooted each time you wanted to switch modes, which would be cumbersome. So I suspect this technical hurdle is a big reason why Apple has so far stayed out of the hybrid market, and will continue to do so for the foreseeable future.
This last point makes me wonder about Windows mobile apps though... Are they not ARM-based? Or can they somehow run on both ARM and x86 processors?
So anyway, at this point, all I can really hope for in the immediate future is for iOS and its applications to grow in functionality and work more seamlessly with their OSX counterparts.