Anyone who's experienced either FoA or KotOR knows what an adventure element can do for a game. Everyone here who wants the next Indy game to be JUST action is out of their minds. Action games are very limited in what they can provide, as demonstrated in the last two indy games. ET was a vast improvement over the poor excuse for a game IM was. But I found both games fell into tedium with their excruciatingly long levels and uncompelling plots.
Even the movies themselves are a perfect balance of sharp dialogue, action and adventure. The perfect Indy game would follow suit. Take the adventure/dialogue elements from FoA and combine them with the modern KotR design. Then rip out the horrible RPG fighting and replace it with an improved ET fighting engine.
And the most important element of all: Write a plot worthy of the name Indiana Jones. The next game desperately needs a cinema quality presentation: 1. Pre-rendered cut scenes [take a look at what lucasarts did with "bounty hunter" and then look at the crappy cut scenes we got for ET] I think we deserve something on par with the best cut scenes being produced for video games these days, e.g. Warcraft III, Return to Castle Wolfenstein, Onimusha III, etc... as these games have to live up to the movies that we know and love. 2. Cinema-quality dialogue. Westwood hired real screenwriters when they made "Blade Runner" why do we deserve simple one-liners? The potential is going unutilized. 3. I can't stress this enough: a plot worthy of the name Indiana Jones. The Indy games are the only narrative manifestation of Indy still being produced these days, and I for one need my Indy fix.
There are plenty of straight action games out there, we don't need any more of them. I refused to accept that only action games can be successful these days. Just look at KotOR! An Indy game that is a synthesis of the elements I listed would not only make for a groundbreaking game that breaks convention, not only be an awesome Indy game, but also A HUGE SUCCESS. Lucasarts has proven that they can make quality games. I for one would like to see some investment in their most neglected franchise.