Robomatter seems to have them in stock. If you were trying to do the exchange it will not help, but if you really need them they have them for the same price as the VEX store.
http://robomatter.com/Shop-By-Robot/VEX-CORTEX-Robots/Hardware/Communications/VEXnet-Key-2.0
According to VEX Sales, "We will have them back in stock next week. "
The VEXnet Key 2.0 is now listed back in stock on our website with a 1 week lead time. If you put in an order today it will ship by mid next week, so you can have them in hand by the end of next week (depending on your selected shipping speed).