I think there's definitely potential with the interface, I for one really like the animations (powerpoint slides scaling automatically and smoothly as you resize the window is pretty slick, and frankly the desktop GUI in general for Windows really needs a touch of this smoothness), and some of the design choices are nice. For example, sliding panels in for certain elements as opposed to a separate pop-up window - albeit it's not very consistent. I also really like the dissapearing scroll bars and borderless windows, while that deviates from the Win8 desktop I have no problem with that, as I think the Win8 desktop is horrifically ugly and a big part of that is those ridiculous window borders. Office 2013 gets far closer to the Zune aesthetic than the Win8 desktop does which is a better end goal IMO.
But yes, MS seems to be really on a monochromatic kick with their professional UI's lately, but the problem is deeper - someone at the top needs to be a design czar and have final say in this. MS has always needed this, but especially now if they're going to tout they believe (meaning, we can make $$) about design. I mean really, how does stuff like Visual Studio 2012 get released in that state? Why in the hell did they have to get an avalanche of "WTF?!" feedback to even add a hint of colour in the icons? Colour helps differentiation is a concept that actually needs metrics on for MS to understand it?
The continual "focus on content! focus on content!" is seemingly robotic in that it negates to mention that sometimes that interface needs to be just as discoverable as your content, as in content-creation apps, you don't have content until you're well into creating it. To do that effectively, the interface has to be pleasant to use and look at. For consuming that content once you're in the app, sure - get out of the way until necessary. But for content creation apps, I don't feel the interface should be trying to blend into the background. Don't make it garish and flashy, but make it distinct.
Oh, forgot to add - despite the blinding-white interface, it's really troubling to see another desktop app, like IE10, that's either not using Cleartype at all or using a sub-optimal greyscale version of it so we can accommodate Windows tablets. When 300+ DPI screens are cheap and plentiful I'll understand it, but we're many years away from that. That alone is going to generate a slew of negative feedback from people wondering why their text looks so crappy.