I have run the developer release, the customer preview and now through my Technet Licences I have the RTM version up and running - to be fair to MS those of you who tried the demo versions and not seen the final RTM will notice the difference - the metro interface is smooth, not buggy, there is more software now that will integrate into the new UI, plus they have done some 'under the hood' tweaks.
Saying that, it's not for desktop PC's - I think we all know that - it's designed for phones and tablets and for internet enabled smart TV's. Seeing as though most businesses still hang onto XP they are not going to make the jump to W8 - from what I see a lot of businesses are looking at alternatives such as Linux.
NOt sure what the support cycle for W7 looks like, but the home market probably won't see a massive shift to W8, but it will be a gradual market gain as people by a new PC/laptop that has W8 preinstalled.
Not enough to get me off my Suse 12.2 install i'm afraid!
SGS - CyanAOSP 4.4 KitKat
SG3 - Slimbean 4.3