People always think it's Windows Mobile, not Windows Phone, so they won't touch it. You go into stores and half the reps are calling it Windows Mobile, and Windows Mobile evidentally raped their cat with a stylus. ****, when you have tech journalists who refer to it as Windows Mobile, what are the average Joes gonna call it? When I show my phone off, I always reference it as the new Windows Phone, which seems to distance itself a bit more from Windows Mobile.
In a more ideal world, the team that branded the Zune could brand Windows Phone. They'd call it something that would sound like the way you feel when you smell freshly cut grass on a lazy Saturday afternoon. Something that would evoke the smell of barbeques in the distance, and wasting the day away with friends in what years later you'll realize was a really crappy car. And we'd all love it.
But in our sucky world, we're bombarded with new products all the time, and it's hard to make them stick in our brains. Companies have to reuse successful brands and append differentiators to them to set one product apart from another in the same base brand. Apple does this to great effect with their i-branded devices, the letter "i" seemingly meaning nothing yet if you stick it in front of a product, people will instantly expect that product to have something to do with the iPhone or iPod.
I get the complaint some state, that there's no windows in Windows Phone. But the word "windows" in the computer space moved beyond a GUI metaphor years ago, at least for me. I associate the word (lol "Word") with an operating system. Windows is something I run programs on, so it makes sense to call their phone OS "Windows Phone".
The real trick here is moving Windows Phone beyond the memory of Windows Mobile.