I use PC at work. I could be wrong about this but I thought iCloud Keychain stores all your password logins and passwords and your Apple ID unlocks all these. So when I'm at work I assume I open(on the phone) my settings or my iCloud Keychain app and enter in the only password I have to remember and get a list of all the sites I have login info for. In the future, I imagine your fingerprint will unlock it instead of your password. Sort of like what they did for the iTunes store. No more password, just a fingerprint(although I will admit I have heard multiple people complain on the internet about still needing a password, seems like a software thing that could be easily fixed though).
You have 20+ passwords and you don't need to write them down? You are a small minority. I assume, again I could be wrong I don't mean to preach I'm right but at a certain amount of password/login combinations(maybe 10) people get frustrated and get multiple errors logging into sites before they guess the right one. I know I do that all the time. You have to think of how the general public will use this stuff, not me and you the tech enthusiasts on a Apple rumor site who are up to date with everything.
I hope the Mini doesn't get heavier but the iPad 3 with Retina did coming from the 2. We'll find out very soon!
I think you're wrong about people using iPads on the go more than at home. Of course on a train you'll see lots of smartphones and tablets and maybe a small amount of laptops. What about all the people that walk or drive to work? Can you honestly tell me that out of all the people you know with tablets the majority of them bring it with them almost on a daily basis? If so, that's shocking to me.