In the US not eveywhere had stock of every kind of iPad.
Some only had 16 wifi. Some had no 3G at all. Or only 64GB 3G or only verizon.
Some places had only 3G and only 5 iPads.
The point is the demand in the US was one country and apple basically sold out.
People arriving at 3pm were not getting iPads. Even 2 hours in advance was too late at Apple stores.
So you have a choice - queue at Apple from 1pm and you can probably get any iPad 2. Any later and you may not get anything. Queue somewhere else and your taking a chance. You may not get an iPad as they don't hav much stock or they may simply not have the iPad model you want.
They were expecting the US release to be less than last year and it was BIGGER. So now you have around ten other countries PLUS the UK on Friday.
It WILL sell out. I promise you.
I would personally place an online order with credit card which won't b pe charged until it is shipped and then go a queue as well. That way you are covered shoji you strike out online.
Exactly what I'm doing except I'll be queueing from 9-10am