I did a little test and put all of my "wait" movies at the top of my queue. I ordered them like this: Very Long Wait, Long Wait, Short Wait. I sent back 3 movies yesterday. They received them this morning.
Much to my surprise I logged in and looked at my queue, and it says that they are shipping Ratatouille (Blu) and The Matrix (HD) today. The Matrix has had a very long wait since it's release, so I was really surprised to see that one being shipped.
PSN ID/XBOX Live! Gamertag: BiffCo