I'd wouldn't pre-order from Amazon. They have proved to never meet the release date for me. Cant say anything about SonyStyle, but I too will be hitting up WalMart on the 21st.
"I don't wanna see that!" -Aunt Sassy (as played by Valerie Cherish) on Room & Bored
I, too, preordered from Amazon (mainly because I had a gift certificate.)
Side note, I hadn't seen the fleshed out list of the extras until this thread (they must have updated it since I ordered). These extras sound amazing - and there are so much more than I expected!! Fantastic.