The same thing happened to me, mosnab. I added all three of the wave to my cart and everything was fine up until I got to the final confirmation page, where I got the "Estimated Ship Date: June 15, 2005" message. So, I went ahead and cancelled the order, as I've had many similar situations on Amazon/TRU where I get the email in about two months time saying something along the lines of, "We apologize for the inconvenience, but the item(s) you ordered are no longer available from our distributor."
All three of the figures (at least when I was looking around) are no longer listed on the main ROTS/SW store pages either. I was only able to find the Vader/Palp-Yoda through the links you provided, and Ventress only through clicking a "People who bought the items in your cart" link on one of those pages.
On a completely unrelated note, I'd just like to tell everyone again how great the Unleashed Obi-Wan and Anakin figures are when you put them together. Even if you're not a regular Unleashed collector, these two figures make one of the nicest displays you could ever hope for in your SW collection. The Grievous is great too, but for me to see so many of the Anakins and Bens hanging around on pegs is disappointing, as they are, taken together, the nicest and coolest Unleashed figures that have been done in the line, period. I'm not trying to "thin out the pegs" for future waves (if I did that, I would have to beg people to buy Securas/Bossks/Tuskens), but I'm just wanting to let people know that there are two really cool toys on the pegs right now that I think a lot of people are overlooking.