I saw that site too...But if they drop ship, we're SOL. They may not be aware yet that Parallax has discontinued these. Damn. What a shame. This puts a SERIOUS damper on those that want to animate servo controled props if they only have a USB port.
Also, if they are coming out with a new design, why discontinue before introducing it?
I didn't think of the drop-ship aspect. And it does seem odd that they would drop the product since USB is the standard I/O port. There haven't been many PC's in the last 5 years that have a native serial port on it.
Of course you can always add a USB-to-serial adapter. I've seen them for less than $6 at monoprice USB to Serial Convert Cable - 3FT .