I welcome a shorter Descent but I don't like the idea of a set of over simplified rules to make it possible, I don't wanna loose potential strategy or it will feel shallow.
There are two aspects of the original 2e announcement that you seem to be combining into one thing here, and I'm not sure that this is accurate to what FFG is doing. The two ideas are these:
(1) the rules have been streamlined.
(2) the game play has been shortened.
Now, obviously FFG hasn't told us very much about exactly how they've changed the rules just yet, so understand that I am not speaking from an informed position here. I'm merely voicing my opinion about what they've said.
From what I can tell from the original announcement, the primary thing they've done to shorten game play is that they've added "plenty of convenient stopping points" to the quests. To me, that sounds like they've incorporated some sort of "save game" mechanic, like Road to Legend had. Each individual quest could in theory be just as long (or even longer!) than 1e vanilla quests, but there will be frequent positions where the hero party can stop and record their progress so that the game can be packed up and put away, to be completed some other day. That might mean that a single "quest" involves a series of short dungeons akin to AC dungeons in 1e, or it might mean that the single large dungeon is divided conveinently into chunks that can be played through one at a time. we don't really know. However, the upswing of this method (in addition to having been proven useful in RtL) is that it shouldn't impact complexity or depth of game play too much while still allowing those of us who only want to play for one or two hours at a time to have our fun.
A lot of people are making hubbub about the "streamlined rules" meaning that 2e will be "dumbed down" to run faster, but I'm not at all convinced that's the case. I mean, I can't say for sure those people are wrong, but I'm fairly confident that history will prove them so. I think that by "streamlined rules" they mean "we've thought about everything we tried to do with 1e, trimmed off the excess fat that didn't work so well, and are now presenting a unified rulebook that is designed from day one to work with everything we've kept in there." It will be less complex in the sense that it probably won't have as many items, as many types of traps, etc. Not in the sense that they've significantly cut down the core game engine. In fact, based on the fact that figures will apparently be rolling defense dice in 2e (instead of using a mostly-static Armor value,) and all the extra numbers on the hero sheet we've seen, I'd say the core game engine looks like it's growing!