I'm not to sure about this now. 3ds-flashcards just emailed me and said that they won't get the OS until after the pro arrives.
Source: 3ds-flashcard.comXecuter SX OS will come out on 15th of June, we will get them from TX on that day or one later later, then we will send SX OS to you in the firstly We will just E-mail you it, no need for Shipping.