Together with whatever New Expansion that will hit the market next, I think it would be cool if the designers threw together a "WOTR Scenario rulebook".
I e, alternatives setup, using the original rules & minis. Something like Saxon suggested under the "Shorter Scenarios" thread, in the "Expansion Ideas" subforum. Like, the situation, on the eve of the Breaking of The Fellowship, when FSP was in Lorien etc!
The good thing is that it is possible to acheive with a minimum addition of extra units & special rules , etc, so it could be added as a "bonus feature" to whatever other Expansion that the designers want to market.
I think Perry's idea of a "scenario booklet" could also be used for new "what-if " set ups.
Given that the setting prior to the start of an actual game of WOTR depended on a lot of chance encounters, misinformation, etc. it should be relatively easy to build either full new scenarios like "what if Frodo set out from Bag End on June 22nd", "what if Gandalf was still imprisoned at Orthanc"; or to allow each side to secretly pick one among a set of "variants" before the start of play, introducing a slight change in set up. The "variant" idea is probably more conducive to game balance, while the full new scenarios would require less departing from the book.