Others have posted about this in other threads, but since you're asking...
Here's my take on olive oil in deep dish:
Extra virgin olive oil has a low smoke point, so is not typically recommended for high heat or long cooking times
(Sorry, Rachael Ray. You're not supposed to use EVOO for everything).
Deep dish pizza involves both high heat AND long cooking time,
which is probably the main reason most people use a more refined 'classic' or regular olive oil.
I use a combination of olive oil and corn oil.
You can get more details about oil smoke points including a good amount of info on olive oil at:http://www.whfoods.com/genpage.php?tname=george&dbid=56
I've noticed there are fairly strong feelings about the type of olive oil being used in making a deep dish crust. It seems the general consensus is that extra virgin olive oil should be avoided. I am curious to know how many people feel this way and their reasons for it.