If anyone's to blame, it's the people of the logistics end of things who can't make up their mind when a shipment is going to go out. The web developers are largely blameless. My guess is they're overwhelmed with the scope of their first major (and overall record-breaking) iPhone rollout.
This release has nothing to do with the crapiness of the site. It's always been this bulky and slow for a year or so now (probably longer). Their incompetence is just more apparent when you actually need to use the site.