I try not to be too confrontational here, but in this case I'm probably going to have to. I would dearly love for Microsoft to release a killer OS, but so far as of yet I can't see any real compelling feature that I would be particularly interested in.
Let's be honest here... if I have to do development work, then I'm not going to use Windows 8. I'll be using Windows 7.
Why not use windows 8? It has lots of small improvements to windows 7 (better task manager, better multi monitor support, new keyboard shortcuts, integrated cloud storage...etc) that's enough for me.
Plus the new Windows runtime APIs looks very nice, and most are usable in desktop or metro apps.
From an end user POV: task manager is fine in windows 7, for any deep system performance troubleshooting I use perfmon; multi monitor support is work brilliantly for me in Windows 7; I use Dropbox, works very well for me and is quite integrated enough!
As for Windows runtime APIs, it depends on whether I want to make he bet that Windows 8 is going to be successful enough to learn them. Jury is still our on that. Besides, I'm more of a Spring man...
Let's be honest here... if I have to do development work, then I'm not going to use Windows 8. I'll be using Windows 7.