OP, if you think a random smattering of replies from around the US is going to remotely reflect your personal wait time, you're crazy. You think you'll get an iPad in London by queuing up at noon? Try noon the day before. Maybe even earlier. Here in NYC the lines STILL start the night before the store opens 8 days after launch.
A. There are retailers who had iPads in some very small cities and towns (compared to NYC or London) people in those places could easily have lined up a couple of hours or even an hour before 5pm, gotten a good place in line, and obtained an iPad. In a smaller town, you could show up at 2pm and be 18th in line as mentioned. But in NYC if you showed up at 2pm you were probably no better than 500th in line.
B. Whatever happened here will happen 10 fold or more on the international launch day. Here in the US, we had no real idea how popular the iPad would be on launch day. If everyone knew in advance, the lines would have been far longer. Lots of people thought the iPad 2 would be a sleeper and planned on waiting to see the initial reviews before buying, or assumed they could just waltz in the next day and get one. Those people now want one and will be waiting a quite a while to get it.
The world has seen what happened on launch day here, and what has happened since a considerable shortage. Be prepared for a much bigger turnout over there.
Tbh I wasn't planning on queuing up at either of the Central London stores as I know for sure people will be queuing maybe even as early as the day before launch.
I'm planning to drive to one of the shopping centers on the outskirts of London... sure there will be queues but no way as long as London.
Whenever I've started queuing 3 hours prior to an iphone launch, I've always been about 30-70th in line, and I'm hoping this is the case again.
Though, because there are no reservations like with the iPhone I might now just start queuing at 12 or 1 now