Microsoft losing its mojo? I doubt it, the real problem is others are catching up to them.
Back in the 90's, Windows was king, and there wasn't a such thing as an iPod, or Blackberry. Fast forward to now, and everything is portable: iPods, Androids, tablets. Microsoft hasn't made much of a foothold in the mobile space yet. The tried (and epicly failed) with Zune, Windows Mobile didn't make waves, and the current WP7 isn't really doing that great either. MS' main economic backbone is Windows. Sure they have the Xbox, and WP7 and other stuff, but if you kill Windows,you'll kill MS.
Teh 360's faulty hardware was a big blow to Microsoft (at least in the video game sector), but that's okay. They weren't a hardare company to begin with.
Now we have Windows Vista; the trashiest OS on the planet. Microsoft may have lost otheir mojo around this time, but they regained it by the time WP7 rolled around. Windows Phone seemed so fresh compared to iOS and Android. It's fluid, clean, and fast. To top that off, Metro looks sleek on it. Why people aren't buying it? That's beyond me.
Windows 8 may just be a response to what I said earlier: everything is portable. The menu on it looks like something on a tablet. From what I've seen, it looks fresh and new just like WP7, just because it's different, doesn't mean it's trash. Long story short, they aven't lost their mojo.