I7 3770k is a better processor, it been discussed before and the ivy brigde have aslight advantage over the 3820,
But if u have the attention of the upgradeability in near future, take the i7
So u can upgrade to ivy bridge-e that i do not know if it have 8 core or 8 core with 2 disable core.
If u work is that demanding it might be useful for 2011 , if it not, get the ivy bridge.
But it always good to have extra horsepower if u have the money.