They are being released on 11/9/2006 but only for a few months. Each film comes with 2 dvds, one of the original theatrical version and one with the enhanced version.
HMV has been the cheapest place I have found so far.
for the UK anyway...
http://www.hmv.co.uk/hmvweb/displayProductDetails.do?ctx=280;-1;-1;-1&sku=527041
I am dubious as to the reality of this being a strictly limited thing but whos gonna take the chance??
Liam