Microsoft should do an experiment with WP7, like they did with Windows Vista, when they showed it to people and told them it was a new OS called "Mojave" to see how they liked it. Without the Vista name attached, the updated/fixed Vista was very popular, everyone liked it.
I'd love to see some "blind" test studies done. Just show people the phone, let them play with it. Don't tell them it's Microsoft or Windows, tell them is a new smartphone called XMetro or whatever you want. Then see how they like it after using it for a while.
I had to put some bias aside myself. I'm a long time Mac OS user, since long before Mac OS X... (I started with an Apple II+!) so the Microsoft knee jerk hate reaction was strongly ingrained for me.
Windows 7 was the first product that truly helped me put that aside. It's very well done, I still prefer Mac OS X to it, but it helped me see that Microsoft can make truly intuitive and well-designed software. I pretty much hated Windows XP and every version of Windows before it (and still do) but Windows 7 is a huge leap forward.
After trying out Androids and iPhone, I finally settled on an Android, which wound up being a terrible experience. All along, I kept playing around with the Windows phones in the store and almost every time, I kept coming back to them, I just liked the interface better, the keyboard and autocorrect worked better by far than any of the others and the Metro UI is so much easier on the eyes, it just looks like it's 2 generations ahead of the rest.
So I was leaning heavily towards a WP7. The thing that finally made my decision easy was seeing Nokia enter the picture with a beautiful phone (Lumia 900) that wasn't just a recycled Android, didn't look like another black slab with no personality. That combined with Microsoft and AT&T's renewed commitment to the platform gave the the confidence to jump in with both feet and so far, so good, I am very pleased with my choice.