I have seen BBC news stories stating that seperate tented areas will be set up to process all the Olympic sporting competitors from around the globe with regards to customs and immigration, especially considering alot of them will be carrying special equipment that they will need in order to compete, rifles and pistols for shooting disciplines being one example.
I don't think the number of border staff or lack there of is the real issue regarding the time spent in immigration. I spent 2 hours queing in Orlando Florida, all the booths were occupied by border staff, grant you alot of flights had arrived at the same time, but the real issue is how much time is spent questioning each person when they get to the immigration officer. After arriving at the front of the que, I was, as a tourist wanting to watch a shuttle launch, (it got scrubbed, so I was back a few months later for a night launch - most spectacular thing I have seen, period!) was subject to something not dissimilar to a mild interogation which took a good 5 minutes or so. Multiply that by several hundred passengers and it all adds up.
have come under alot of criticism lately for lapses in immigration security over the summer in 2011 IIRC where the level of screening was much lower than it should have been. Now it's back to where it should be, but this creates long que's as a result of the thorough screening process and has been mentioned earlier, money is too tight to mention - cutback.
First impressions are everything, unfortunately UKBA
will be for better or worse the first impression alot of the worlds tourists and Olympic Competitiors will get of England in 2012.
It's a balancing act that has compromise written all over it, no matter which way you look at it.
(Edit) Also I want to add that no matter how thorough the UKBA is, MI5 is going to have there hands full with the home grown terrorists this summer.
[Edited 2012-04-28 04:55:10]