My iPad 4 with Wi-Fi + Cellular (64GB, Black, AT&T) changed from "Processing" to "Preparing for Shipment" yesterday afternoon. And, of course, I was charged for it... they won't start to ship anything before they get paid for it. (Apple didn't build a $65 billion+ cash reserve by running a charity...)
I called Apple on Thursday and got my shipping changed to 2-3 day. Next-day air was allegedly not an option, even though it appears that some people were able to get that upgrade. My original delivery date was the 23rd, but now it's the 21st. If historical precedent with my iPhone pre-orders shows anything, I expect the iPads to ship out on Monday or Tuesday, and arrive by Friday or next Monday.
This will be my 3rd iPad. I had an original iPad (64GB, Wi-Fi only) and an iPad 3 (64GB, Wi-Fi only). My original on-the-go data strategy was to simply tether to my iPhone, but over this past summer I became somewhat frustrated at having to finagle the wi-fi connection between the devices every time. By the end of August, rumors of an iPad refresh were afoot. So I waited to upgrade until the *NEW* new iPad was official.
And now that I've moved to a mobile share plan, I'm more than happy to pay only $10/month to tap into my data pool.