I have the pleasure to announce that TheCartPress (ecommerce plugin) added support to work effectively in WordPress 3.0 + networks installations.
The user is automatically registered as the role of customers without email confirmation and the purchasing process and the flow is nice up to purchase
WordPress network: we now add the user as a subscriber to the network (WP native behavior) and also we add the user automatically as customer role to sub-blog/store. Then the user is automatically registered without the email confirmation and the customer automaticaly will go to step 2 of checkout to continue the checkout process.
Thanks!