The usefulness and flexibility of arbitrary window sizes, of having multiple small windows visible, of partial visibility of relevant portions of background windows, isn't going to change no matter how much time passes.
It doesn't matter how many other advantages the new app paradigm has; if it remains limited to a choice between fullscreen and "squished into a sliver on the side of the monitor," it will always be useless to me.
Across those three monitors, there are currently six fully visible windows, two partially visible windows, a vertical taskbar with 8 icons visible in the notification area, and 6 gadgets visible on the right monitor to the left of OneNote. All of this can be seen at a glance and changes monitored via peripheral vision, no need to switch to a "Start screen," regardless of which window I'm working in at the moment, regardless of whether my keyboard and mouse are busy playing a game or whatever. The UI-formerly-known-as-Metro can't even come close to replicating that setup.
I don't own a tablet and have no plans to get one.
And even if the 42" HDTV acting as my center monitor had a touchscreen, I wouldn't be able to reach it.
There are some actual appealing features in W8: Storage Space, Hyper-V client, new Bitlocker functionality, UI tweaks in Explorer and task manager.
Unfortunately, the removal of gadgets means I can't just casually upgrade to 8; I'd have to investigate how to replace the functionality I'll be losing from all six gadgets I currently use.
Storage Space is fantastic, but I'm not sure it's worth the hassle of upgrading for just that one feature. Is there anything else interesting in W8?
(Does anyone know if the improvements to Bitlocker allow restoring an OS system image to an encrypted volume now?)