I'm not so sure the demand is there just yet. I've got a 5.0 in my Explorer. One of the most popular engines of all time and perhaps most "moddable" engine that has been in the Explorer. K&N never bothered making a full kit for 5.0 equipped Explorers nor did Volant. The 5.0 ran from 1996-2001.
Given Ford's financial troubles, lower than expected sales on all their models, high fuel prices and the fact people are turning away from larger and less fuel efficient SUVs, I just can't see that there is a large enough '06 Explorer population yet to justify the product development given that a small% of people who actually buy SUVs actually modify them.
I'm using my accounting background for this one. Marketers always feel they can sell something. Beancounters temper than enthusiasm.