Capcom said each of the three campaigns will last a little less than RE5, which is awesome. Ada is likely to be an unlockable scenario. And then you have Mercenaries and other extra modes along the way.

Mercs will be awesome considering the maps are so cool looking

My take:

RE5 lasted me almost 8 hours.

Leon: 7 1/2 hours.
Chris: 6 hours.
Jake: 6 1/2 hours.
4th: 4-5 hours.

24-25hrs, not bad at all.

We also have the Mercenaries and most likely Versus.

I'm hoping Leon's is the longest. I read somewhere that the decisions you make in one scenario will affect another. Anyone know if this is true? It'd be cool to make different decisions each playthrough, increase replayability. Just not sure how it'd work.

Hopefully they don't get carried away with stupid online modes like on RE ORC

The Campaigns In This Current Gen Games Seem Shorter Because The Games Are Easier Than Last Gen Games. Also Where Like The Old Resident Evils or any Game, They Didn't Tell You Where To Go. So You Had To Search Every Nook And Crannie On What To Do or Where To Go. Games Now A Days Always Point You In The Direction You Have To Go, Most Games Also Have Become Easier For The Casual Gamers and Are Linear. Take A Look On How Long It Took You To Beat The Old Resident Evils The 1st Time. Now How Long Does It Take You To Beat Them Now. Where The 1st Time It Might Of Took You Over 10-15 Hours, but Now It Probalily Could Take You Less Than 2 Hours, Even RE4 You Can Be It In About An Hour and A Half On A New Game. A Really Good Example For Not Knowing What To Do or Where To Go is Dino Crisis 1.

Not really sure they are easier. When most of us started playing RE, we were young, and naturally games are harder. You are able build better strategies when you grow up, and that helps a ton in games like these.

ORC didn't get carried away with its online modes (stupid or not). The game was practically built for online play. I personally think it could use a few more online modes like co-op survival (attacked until everyone dies) instead of just versus themed matches.

The old RE games were longer because of puzzles and no real guidance to where you are supposed to go (except if the game wanted you to know by showing you the map and blinking the room red), but it was also longer because of a lot of back tracking. Oh I need this or I can't hold this so I'll be back to pick it up later. This day and age, a lot of gamers lack the patience to back track and have very limited item space. Though it was fun for me to do that, there is no appeal for it these days. I feel old saying that... "these days"...

Also guidance to the objective never bothered me. It's easy to not pay attention to it when you want to just explore. All that guidance tells me is that I want to go that way when I am done looking around.

I find it hard to believe the idea that this will last 20 hours, particularly when they are bringing forward the release date. Around 4 hours per character is more realistic. After all they are trying to sell this game as hard as possible - Capcom will over estimate as much as they can.

^
Exactly. 4-5 hours each for sure. Praying there's no way point markers, but I already seen one in the latest trailer :/
Ada's scenario better not be DLC -_-"