So I tried Windows phone 7 for 6 months with the HTC Radar 4g, but went back to Android and picked up the HTC EVO LTE (One X for Sprint). I'm hoping Windows 8 does well enough to be a viable 3rd competitor. Here are things I hope to see in Windows phone 8:
Faster start up times for third party apps. I always hear how fast Windows phone 7 is, but to me that's not true. It's smooth, but I wouldn't call it fast.
More developers getting on board. I don't care hearing about 100k apps in the marketplace, but I do want my banking apps and Yahoo fantasy football app. Going to the website is not as convenient.
Better notifications. I hate getting a notification, and if I don't have a live tile for the particular app, I have no idea what the notification is for. This looks like it has been fixed in Windows phone 8 - there's notifications on the lock screen, and it looks like phones can now have an led light for notifications.
As long as these things happen I'm open to getting Windows phone 8 for my next phone. Specs have caught up (720 screen resolution, Qualcomm S4 Krait processor, etc) and are good enough.