I know, it's a bold statement. But I feel it is true, and here is why. There are too many 'iPod killers' out there. The market is saturated. Apple made a device that was a revolution in the technology sector. They did it, and were unique and innovative at a time when no one else, or very few others, where there. They did what Apple does. They made a cool looking device with neat features and they listened to the customers in what they wanted in their device.
Now we have every maker of flash memory, several who just make electronics in general, and several others who just have nothing to do with their billions, primarily Microsoft, jumping in to the market. Here is the problem, and it's the same one that anyone trying to dethrone Microsoft from it's market share, in Office and OS. Linux could have dethroned Microsoft. I firmly believe this. The problem is that there became too many flavors, too many different things for different tastes. Microsoft, for all it's bad things, does one thing very well. It generalizes very well. It gives each person a few things they want and enough functionality to be acceptable, even if they do it at the cost of security.
Now we transfer the analogy to the MP3 player market. There is one dominator (Microsoft Windows>Apple iPod) and a lot of competitors trying to dethrone them (Linux distros and Mac OS X>MP3 Player makers like RCA, Creative, Samsung, and more). The market is too diluted to have any chance. Microsoft is said to be the latest 'best chance' and their media player is said to be the best chance in a long time to combat the mix of iTunes and the iPod, but it has it's own issues. It is riddled with annoying and obvious DRM whereas Apple's DRM is far less obtrusive.
Yes, you need to authorize a computer or device, but after that the DRM is nearly invisible. When it comes to WMP, at least the last time I used it, it had to contact sites, and 'obtain a license' for each item you want to play. Now what if you're on a plane? How will your Zune be able to obtain a license? The version of WMP I use checks repeatedly, even on the same file played again, and it is a long process when all you may want to do is listen to a 5 minute track.
Also, the WMP program is very hard to convince to rip songs to a proper MP3 format, instead of DRM added WMA. Often it will, upon a unconnected patch, reset it's settings to the default, which of course means that many people, unless they check, rip much of their collection into WMA files which lead to DRM hell when their PC's have issues. In the end the Zune and WMP are not the thing that will bring down the iPod. It would take most of the products on the market dying off, leaving 1 or 2 good products. Then the huge market share that Apple has might be at risk, but even then it would only be likely that the 2 or 3 would split the market much like most technology markets.

I will believe it when I see it. Until then, I'm with you.