The Deluxe Edition has now been unavailable in the Store for over a week.
According to another forumer, Telltale said:
"We've had some trouble with the Deluxe Edition so we had to take it down from the site. It's out of stock and it's not certain when or if it will return."
It's my contention that Telltale would make it available again (if only for a limited period of time) if they saw that there is still an interest for it (I believe that making the extra parts for the Deluxe Edition takes time and costs money, and that Telltale would need a certain amount of potential Deluxe Edition customers for it to be profitable, especially as they probably have to share the profits with LucasArts).
So, here's a friendly poll to help them gauge that interest.