Okay, I just HAD to register, so much misinformation in a single post.
For a start a lot gamers won't be happy to find out that their older DX9 titles that require DX 9 elements won't run on 8! At least with 7 despite DX 11 you could still install 9 along with it and the old stuff will run. Then of course 8 being a newer not so compatible as the 7 from Vista move is not able to run many other things that run on 7 without some newer version coming out.
The change from XP to Vista was also a leap while Vista and 7 stayed much closer compatibility wise. There are a number of things if you look close enough that run on Vista and generally will work on 7 but not 8! But this is also the expected outlook when going from any version to one newer.
As far as Tablet PC no one would expect any optical there or with a netbook. Plus Tablet PC has always been a totally "separate" edition from what goes on any laptop or desktop to begin with. Why would anyone want Tablet PC gui on a desktop pc when they would expect a newer desktop OS to have a desktop gui to begin with?
As for the Media Center that was one thing added into on the 2005 XP MC edition and simply carried on with Vista and 7. WMP on the other hand has been around since 95! WMP 10 finally saw additional codecs included rather then the need to go and buy separate codecs online. Now MS is eliminating the ability for playback entirely? not just removing codecs!
That's another "why?" to add to the list which will make many wonder why bother?! Most will simply look at 8 and think MS is "off in the clouds somewhere" not paying attention to the desktop user!
Generally whenever MS make a major change in the OS it usually takes a few versions to get things worked out. That was seen with 3.1 to 95. 98SE however was the Legacy winner! Likewise following the leap from XP to Vista 7 topped all! And we now wait for 9? 10? 11? to fill in the void between 7 and...
Did you actually TRY Windows 8? Cause it doesn't seem like it.
DirectX 9. Where did you hear that DX9 (or older) games wouldn't work? Cause mine all work fine. In fact, games like Diablo 1/2 and Starcraft work fine without any work arounds that were needed in Vista/7.
Compatibility, both with software and drivers. Haven't read of any significant issue with any software, save for a bug in Skype. Drivers? If they work on Vista/7, they'll work on 8. My old B/G wireless card works fine with the drivers that came on the CD. Had no issue installing W7 drivers for my older system, either.
Both Nvidia and AMD have been supporting CP and RP with beta drivers and there's very few issues so far, save for one specific game I've heard of (Max Payne 3).
Tablet UI? Eh? Click on the desktop tile and you've got your regular ol' Windows desktop. The start screen takes up the entire screen, yeah, but when you go in your start menu, you can't do anything else ANYWAY.
Do you just sit there with your start menu open while looking at a Youtube video or whatever? I doubt it.
Pin your most used apps on the taskbar and pin the rest on the start screen and that's it.
You're not required to use Metro Apps. It's not the most elegant way of doing things, but it works.
Media Center... Eh, never seen anyone use it, most people just download VLC anyways. And WMP is staying, unless you're talking about Windows RT, which is for ARM based tablets, in which case they have the Music and Video apps to fill the void.
Oh and btw, paying for codecs? Really? Who does that. There's plenty of ways to watch any and every video file imagineable. VLC and MPC-HC being very easy ways to go about it.
And I wouldn't call Windows 8 a major change. The only real difference is the start screen, which works more or less the same way as the start menu, except it's fullscreen and you can have pretty tiles that show random info like new mails, weather, news and stuff.
There's lots of behind the scenes improvements, but they're hardly a major change, either. At least IMO.