We were at very beginning of the release back in 2008 and 2009. Why is 2010 different? We have a few more carriers, sure, but the UK isn't any different. We're the closest country to the US.
Why June 24th and not June 18th for US? Sucks man, but its life. Besides, July will be here before you know it. Wait, I'm lying it will seem long as f#ck like the wait for WWDC 10' was...oh well.
Kidding of course but it is pretty stupid that the Great White North is not getting the phone at the same time. Maybe Steve is still pissed that Canada won the Gold in Hockey.
I suspect it comes down to sales of previous models. If your country did not man-up and purchase enough iPhone 3GS phones then you get bumped back this time.
Some people are too spoiled..Many people in Europe (like me) will have to wait until September, probably. And I am not making fuss. Be patient. You will get it in Canada sooner than many, many other countries.