[flyingsaucer]

Overstock.com has a very similar setup. First step asking email username, seconda step the rest. Also notice on both checkouts, they have extra info boxes on the side assuring the customer that the checkout is secure, and urge them to complete the purchase because the items maynot be available when/if they come back.

These are clear indications that they spent some time to figure things out and optimize checkout.

Checkout is VERY important.

Another thing about checkout is, I noticed when customer enters an invalid card number xcart still displays that "order being processed" screen and places the order as failed and sends email out to user. What is the point here. All it does is to confuse everyone.
If the transaction is invalid, just show error and thats it, why place an order in database and set it to failed, and more importantly, why send an email to customer?

I think these should be done once they come to the successful order placement screen.

As a new xcart use, finding out weird stuff as well as very nice features.