It is supposed to be a ride similar to all of the slow or still scenes found in mummy, except it will have 3D. In this, it will be a longer seeming ride, with bigger sets and probably many screens that at best (if they get it right), you won't know are screens. Caverns that go on for impossible distances, and canyons that slope hundreds of feet below your track. There will probably be a few mini coaster moments and hopefully a good number of break runs, returns to magnetic control and perhaps even short stops.
The last three sentences are both my expectations, interpretations of inside info and my hopes. There remains a small chance that it will still not rival Spider Man for many. Alas, most don't and can't come close.