A swing & a miss...
I think Microsoft has seen what Apple's doing with OS X & iOS; crossing-over features as is actually useful, and have tried to jump the gun by actually creating a single, universal OS.
It will simply pack a load of UI features not useful on any practical desktop set-up, meaning that anyone with any sense will disable the Metro UI for their PC (essentially turning it into Windows 7); while sacrificing a load of useful functions to slim-down the kernel that will still be heavy for phones & tablets (which will still only run Windows Phone style applications anyway).
Windows 8 basically seems to be Microsoft's attempt to make Windows 7 & Windows Phone 7 meet in the middle, but it has just been left with the worst aspects of both! A mobile OS that can (usefully) do no more than the previous version but drains your battery faster, and a desktop OS that has a clumsy interface (albeit one that can be got rid of if you go to the effort of editing the, *sigh*, registry) and is less capable than the previous version!
The only devices I can see it being worth installing Windows 8 on are Windows 7 tablet PCs, where the Metro UI & trimmed kernel would actually be an improvement. Even then, any non-Metro Apps are going to have the same UI flaws as before...
Visually, personally, the Metro UI reminds me a little bit of the LCARS (Library Computer Access / Retrieval System) interface from Star Trek, just with a green background instead of black & sharp corners on the tiles instead of rounded...
I'm thinking that Mike Okuda (the guy who designed those panels, colloquially known as "Okudagrams", for Star Trek) should have words with the Metro development team & tell them to be a little more imaginative!
(Ok, maybe the similarities are a bit tenuous; but I'm a Trekkie, we notice these things!)