How long till Apple makes a touchscreen iMac?

Not without a complete OS re-design, meaning nearly trashing OSX... Look, even Windows8 needed to introduce an app ecosystem in order to promote a touch-centric interface. But core OS life, like windows, taskbar still are out of the scope, Windows8 Desktop Mode is still not aiming at touch. So, i think another revolution would be necessary, despite the technology being completely ready to achieve it.

Among my coworkers there's often the idea that Microsoft should have made the "no-longer-Metro" interface an add-on. Maybe it could be even installed on Windows 7...

It seems to me that if Apple launches an "iOS as an app" for OS X, that allows people to run iPad applications in a sandbox and/or virtual machine alongside Mac applications, it would be a great thing.

I hope never. I don't want fingerprints all over my monitor.