It looks as if the Tabs release date has been outed! Thanks to the play.com link from Duncan, I found this:
http://www.play.com/PC/PCs/4-/164393...t/Product.html

It lists the release date as being November 1st, 2010. The currency is pounds, so I assume that this is the UK release date, but something tells me that other releases will be around the same time!