1/2 of those work on 4.1 and another 1/3 already exist in 3rd party handsets or 3rd party apps
the only standout is multiple users (tablet-only)
If you factor in 3rd party apps and 3rd party skins such as custom roms, then the majority of improvements in Android (beyond performance improvements) have already in one way or another been implemented. That doesn't make the improvements in stock Android any less true however.
And the first half of the list made Android worse.
- new camera app
- new clock app
- new gesture-typing keyboard
- lockscreen widgets
New camera app, full screen, HDR, and photosphere as standard. Worse than 4.1 camera? Nope.
New clock app. Built in timer and stopwatch. Some different font and stylistic choices. At worst, no better than 4.1, but certainly not worse.
New gesture typing keyboard. You can still type normally, or use gestures. This is by no sensible assertion worse and the gesture typing is solid.
Lockscreen widgets. Made a widget called dashclock possible. Is Android worse because of it? Nope. The lockscreen is now what you want to make of it.
Honestly it's valid criticism to say that the lock screen needs further refinement, but it's a definite improvement on the non customisable screen in 4.1.
There's a whole lot of cognitive dissonance going on if you are saying that 4.1 is an improvement over 4.2.