The only time the new UI really sucks is when using remote servers via RDP. Someone should be sacked for the decision to metro-ize Windows Server. It just makes you do complicated mouse movements, as the winkey gets sent to the host box except in fullscreen.
The part I'm hesitant about is the ugly "flat" look. In Win7 and Vista, Aero was a premium feature you had to pay extra for. Now they just stripped that, and we're left with window chrome that looks like your palette just took a bit depth reduction.
I use the start menu fairly often, and the mouse constantly i guess. I'm not sure I've ever seen a windows user who doesn't do the same.
(Yes, it does take over the screen when you call it, but it disappears once you launch something)
Put another way, why would I want to go from this:
http://forums.unixhub.net/boards/b/src/1348934524725.jpg
To this:
http://www.superutils.com/wp-content/uploads/2011/10/3-win-e...
If you operate in Desktop mode, when you hit the Windows key, yes, you will see a full screen menu like your second link. That's the one place where, without extra software, Desktop defers to Metro. I'm undecided on how I feel about it. The transition back and forth is virtually seamless & instant, so it isn't a thorn, it's just different.
One upside- because it has much more screen real estate than the traditional Start Menu, you generally don't have to dig through submenus for programs other than your handful of pinned "most-used" list.
I don't use the new ui for work, but I do find it very useful to quickly check things like weather, read news, etc since its incredibly fast.
The biggest fundamental flaw I came across is the fact that you can't have metro apps open on multiple monitors simultaneously. Definitely an odd decision.
Don't let the start screen be the only thing stopping you from upgrading to Windows 8. Give it a shot, and if you don't like it, use third party software to replace it.
I understand full screen on a tablet, but on a 27" monitor with no 'touch'? WTF?
Walking into Best Buy today, I noticed that almost all the computers had touchscreens. Even the few that also had keyboards in front of them lacked mice.
They're clearly betting on the hypothesis that computers in 2/5/10 years won't have mice, those having been replaced altogether by all-in-one monitors.
In other words, I don't think the intent is to get Windows 8 installed on existing hardware. I think the intent is to get Windows 8[1] to dominate (and perhaps even drive) new sales.
[1] Or, more likely, the successor to Windows 8 - Microsoft customers have always had a pattern of 'skip one, upgrade one', and even without the redesign, Windows 8 falls on one of the 'off' cycles as it is.
In any case, I think this was just for display purposes. The touchscreen is intended more to replace the mouse than to replace the keyboard - at least for now.