They sold out on Baalshield, too.I heard at my local GW (after noticing Mordheim and indeed all other GW games were gone from the website) that they sold the rights to those specialty games to Fantasy Flight. I would rather FF make these games, there customer service is... well... actually customer service!
They already lost me on the limited releases though. Voidshield generator was the first of what has become a series of disappointments to me. I am a bit of a completist and when its sold out before I get an email about it it adds -1 enthusiasm to my hobby tracker.
"Hey look how cool this model is!! Sure it comes with a bunch of useless grots and a bunch of Wolfies you don't need but its a new Warboss guy!!! Whats that? you want it? aaaaaaaaand its gone!! But really its your fault for not coming in every week to pick up the new White Dwarf..."