Well, depending on when you put down your $99 deposit, you'll be in different phases.
Phase I is when you put down your deposit
Phase II is when they contact you to customize your model
Phase III is when the put your car on the assembly line and ship it to you.
So what I've heard from an official smart customer service operator, is that if you made your reservation in July or August of 2007, you're currently in Phase II. That means anybody who made a reservation in September or October of 2007 is up at bat to enter Phase II - so watch your email inboxes!