Fulfillment by Amazon would be awesome for this. Free two-day shipping and the site wouldn't go down. Edit: Seriously, you send them a big box, and they mail out all the little boxes. Check it out: http://www.amazonservices.com/content/fulfillment-by-amazon....
While it would have been a good idea to distribute some of the devices from the US that wasn't the main problem. A common way to do a launch like this is: 1. Make people register with their e-mail adress. 2. Send order links with unique and expiring tokens in batches. 3. Process payments.
In addition, the HDMI support means you are locked into a T.V., or a computer monitor with HDMI which isn't as common, and the ARM architecture means most of the pre-built code out there won't run on it.
I was caught up in the hype too originally thinking of everything I would do with it, but basically, it is a slow computer without a case that will have few OS options, few software options, and that you could connect to a T.V. While there is much you could do with that, it certainly puts it into perspective.
A better option for most would be to find a used computer on Craigslist or eBay. However, if you live in the UK and are truly interested in a small ARM computer and have everything else you need to use it, go for it. I won't.