I picked up my PS4 at Best Buy at midnight last week. Basically, there were two lines, one for preorders and one for those who didn't. I went out to my Best Buy around 9:30pm and there were about 10 people in the preorder line and about 50 people in the non-preorder line. At 10:00, they started to let the preorder people into the store in order to finish the transaction sale. This helps so that by midnight, once they let people in, you simply show them the final receipt and they hand you your console and you get out without much fuss. I am in California.
I plan on going out around 9:30pm for the Xbox One launch this Thursday. If you like to grab your console at midnight and hope to get out quickly to get home to fire it up, I suggest getting there before 10pm. If you want to avoid waiting in line, show up a little after midnight and just get in line and you would probably end up waiting for 30-45 minutes tops. Really depends on how quickly the employees get the transactions done and how many people they have at the store.