A simple review
Some disclosure first:
Choice of home pc OS - windows 7 64 bit
Choice of tablet / phone OS - IOS
Works with all manner of (proper) unix systems
Ok, so like all windows fanbois I thought I would hate windows 8 but after trying it I find I am left wondering why they (Microsoft) just didn't release two versions, classic & touch?
I installed the enterprise 64 bit trial on a VMWare VM and gave it a single processor & a gig of RAM, fired it up, installed win8 and got to "work". The NewUI wasn't that much of a problem for me, after all I'm a tablet user so using the tiles, apps whatever you want to call them wasn't such a big deal.
I added an app (mahjong, if you are that interested) from the app store and its here I felt a bit cheated, I got a message along the lines of "mahjong has been added to your start page" (or something like that) and, yes it had, I thought "that's quick" unfortunately, it had just been added to my start screen, when I clicked it then it went off, downloaded it, installed it so the speedy install I thought had taken place was just a bit of a con!
I then took a look at the desktop, seemed a bit flat to me, no aero etc. and yes, I noticed the lack of a start menu but then I realised I don't use the start menu a lot, mainly to find that program I installed ages ago that I can't quite remember the name of so I can browse through the installed program's in the start menu. No big deal, I just pinned the program's folder to the explorer icon in the task bar, not as nice but it's a workable work around (for me at any rate)
So, you have a desktop, slightly different, not as "shiny" but still useable for day to day work and you have the NewUI which seems to be OK for its intended market - touch enabled devices. My main question then is why not let me choose which one I install? On my daily use machine I have no use at all for NewUI, I'll probably never use it on my non touch laptop so why install all the files and stuff I'll never use?
Pro's - for me, personally there is nothing here that will make me spend money on an upgrade and that's from someone who's gone out and got the latest version of windows (yes, even Vista!) whenever it became available. The biggest "pro" from my point of view is that if I HAD to use windows 8 then I could get it set up and working how I want it to and probably never have to use the NewUI.
Con's - when using the desktop I'm used to pressing the windows key, type in a few letters and run the program of my choice, it's going to take some time to remember that the windows key just takes me back to the NewUI start page! I tried pressing L and searching that way and it seemed to work ok so once I've got used to it, shouldn't be an issue (although I did notice when I pressed L to get the search menu windows seemed to leave an L in the search box, I'm putting it down to me using a trial version in a VM, or me doing something wrong, if this is a design "feature" then it's just plain annoying!) when using the NewUI I found arranging the tiles (or whatever they are called) to be very annoying, again it might be me not doing it properly but it seemed if I got the top row looking how I wanted it then moved a tile from the bottom to the middle (by dragging it up) then one of the middle tiles jumped to the top and the displaced top tile appeared on the bottom row!
All in all it's just minor niggles, the biggest of which is WHY? Why install a touch UI on a non touch PC and vice versa, what's the point in having the desktop installed on a touch screen enabled device? I have a pc I use to DO stuff and a tablet to USE stuff, both are perfect for how I want to do things.
Summary
Will I rush out to buy it? No
Will my life be ruined if I HAD to use it? No
Does it work? Yes
Does the missing start menu make it unusable? No
Overall rating - Meh
I would urge all the doubters to give it a try, you might still hate it but at least you'll see it's not the end of the world as you know it!