[Windows 8 General] GoodDayToDie:
Reboot times are a total red herring. It's a waste of Microsoft's time to put a bunch of people to work shaving off another second or two. Why are people rebooting anyhow?? I never do except for updates. Sleep is faster to enter, faster to return from, doesn't require re-launching my apps, uses only trivial power, and is supported on all hardware I've seen this decade (although I did, about four years ago, encounter an NVidia driver whose preferred form of "screwing up your PC..." install process was to break sleep mode, which I fixed by rolling it back).

Now, if they want to make it so that reboots are needed less often, I'm all for that. More user-mode drivers, and/or modernize the kernel-mode driver stack to reduce how often KMDs require reboots (already much better than XP and below, but still too high). Make Windows Update better about not requiring reboot; I'm willing to close a program or even restart the desktop Explorer session (which takes moments) to avoid rebooting the whole machine.

Fix the <REDACTED> Start search. I don't understand why they took one of the best UI features of Vista, preserved it in Win7, and messed it up in Win8, but the whole segregation of "Apps", "Settings", and "Files" needs to stop, now! Launching programs is one of the very few core requirements of an OS, and the last two versions of Win8 were better at it than Win8 is (specifically, they required fewer clicks and showed more useful info at a glance). That's a travesty.

Metro apps and multi-monitor were already discussed. Instead of reiterating those, I'd like to see more capable Metro apps. Currently, they're locked down to nigh-uselessness from a get-stuff-done perspective. Consequently, I barely ever use them... but that's not good for the ecosystem, because it means that I (and people like myself) have much less incentive to develop them, too. One critical feature: the ability to launch other programs without the target being expressly designed for it.

As a Surface RT owner: remove the stupid prohibition against third-party desktop apps. Make it a hard-to-find setting if you must, but let me unlock it without needing kernel-mode hackery.

As a Surface RT owner: give me drivers! The USB port is already useful, but it could be a lot more useful.

As a Surface RT owner: add support for the low-power standby core of the Tegra 3. Battery life is good already but could be better.

Integrate something like OblyTile into the Start screen. Default desktop-app tiles are ugly.

Worth asking for: multiple (virtual) desktops? I mean, it's "just another app" now, right? I hate that in 2013 I still need to use third-party utiltiies to get this feature that all other common desktop environments have.

Please don't kill off the SUA (Subsustem for Unix Applications)! At the very least, open-source it when you drop official support, so the community can introduce some long-overdue fixes. But seriously, that thing is useful. Cygwin is a nasty hack by comparison.

A virtualization environment that supports high-end graphics would be nice. There's a lot of games that run like crap on NT6 but don't run on virtual XP machines using any of Microsoft's virtualization environments. That directly contributes to the market share of third-party virtualization software. MS used to be good at this VM thing for uses other than servers...

Lots more, but this post is long enough as is. That covers most of the gripes I have at least once a week using this OS.