I just thought I'd share some of my experiences with getting signed up to publish to the marketplace. Although the development experience for WP7 itself has been quite pleasant, getting on to the marketplace has had a few hiccups.
First off, it costs money to create an App Hub account, about $100. I think there is some free option for students, but I didn't get into that. I created my account with the same windows live account that I use for my XBox, and during this process they decided to automatically bill to the credit card I had associated with that account. No option was given to select a different credit card. In my case this was an ok assumption on their part, but in general this isn't too great of an idea.
Next, they need to verify your identity. To do this they have a third party provider, GeoTrust, email you and gather some information. After waiting two weeks (or one fortnight for the nerds out there) without hearing anything I looked into the matter a bit more. It turns out that you need to submit an app to the marketplace before they verify you. Additionally, to unlock your phone for testing purposes you need to be verified. I can understand a need for verification, but I don't understand why I need to submit an app to start that process. The process requires you to submit an app which has never been tested on a real device.
After submitting a fake app I got a notification from GeoTrust saying that they will send me some more stuff in 1 to 2 business days. This is where I sit right now.