The 6/17/2012 is a good thing, you are that much closer to your next iPhone upgrade cycle next year....!
(However, it should adjust to the actual day you complete the activation which should be 6/24/2010). See just as you would see the benefite of the earlier date, other customers feel cheated out of those days.
They are not going to ship any iPhone 4 for home activation where the contract has not already started with that new $325 ETF.
Only thing left to you is to use iTunes to activate the iPhone 4, where you agree (click through the AT&T and Apple TOS / Contract terms if the servers survive long enough to support the first wave of "early adopters".
Dave