"If it gets to Thursday or Tuesday"
....WHAT?!
YEA!!!! Haha, see, remember earlier how if you "pretended" to ship a package for China (like UPS agents have been doing to give customers estimates on delivery times?) That if shipped earlier today, it would get to the delivery address by THURSDAY. Now, assuming they do it tomorrow morning? It would "technically" get here by FRIDAY! And what about Thursday? With Saturday delivery it would get to your house on SATURDAY! Even if Apple botched one of those days up, with overnight express international they could send it FRIDAY and have it to your house on time.
What I am trying to say is, while it may sound crazy to you (trust me, it was hard for me to say that lol) there is really no need to worry.
Apple (as I have said 8x times today) has their OWN orders for retail and bestbuys to fulfill. So those iPads have to go out ALONG with ours! So no EVERYONE is getting theirs sent out at once. #1 It would clog up UPS's system and leave iPads stranded at the loading dock in Shenzhen, and #2 Apple is fulfilling their own orders at the same time (seemingly by staggering them).
NOW! To everyone in the "prepared for shipment status" - LISTEN UP! Everyone has gotten their emails overnight between 1AM and 5AM ET (about 1-5PM Hong Kong time). Remember there is a time difference. And that was the night(here) before the shipped. So for me, mine shipped (today, but it was reallly yesterday evening) and I didn't get an email until 5 Am this morning! However I knew it had updated.
Other people also got their emails during the night theirs shipped. Because right now those factories are actually going to lunch or whatever Chinese workers are allowed to do, and so they are half way through the day while we sit here and track our iPads.
IN SHORT - IF IT IS PREPARED APPLE IS SHIPPING IT! If it wasn't prepared, then I would have a huge fuss and would be calling now. But Apple will tell you the SAME THING if you call them now or even tomorrow - IT IS PREPARED - GUARANTEED BY 4/3! (or 4/5 for non-sat. del. areas).
So please try to get over that worry and try to look forward to receiving it - Apple cares about people who pay $$$ for their stuff, so trust me they will make sure it gets to you on time.
I think you are more or less worried because most of the people on here already have statuses. If you hadn't come here or people didn't post about them, you may not even be calling, thinking Apple is just shipping them closer to the release date, which is (still) 4 days away...