In the rails3-selfsignup branch, it is not clear that the user should pay a membership fee. This flow can be much improved.
The user can be logged in after signing up.
After signing up, the next sensible step is to pay the signup fee - the user should be directed to the payment page, where a clear explanation is present of what's happening.
When the user does not pay and comes back, it should still be clear that he needs to pay the membership fee before he can order. This could, for example, be a large and clear sign on the dashboard page.
In the rails3-selfsignup branch, it is not clear that the user should pay a membership fee. This flow can be much improved.