The reason the folders only show 3x3 now is that is all that is displayed in the preview, it always bugged me how thd first icon of the second row became the last icon of the first row when the folder opens. There is no object constancy and this is highly disorienting.
One solution is to leave the 4x3 or even make it 4x4 but just make the preview icons be the top left 3x3. Still they did it for a reason that makes sense, it just feels like a step backwards in a way. The multiple pages within a folder should alleviate this however.
4x4 leaving 3x3 is not a good idea, I reckon. That's disorienting also.
I wonder if it may just be better if the folder pops up that displays the icon preview, and then you just scroll a 3-wide list?
I just don't like the idea of pages of apps WITHIN pages of apps. It makes it kind of too maze-like to drill too deep.
What's next? Folders in folders?
And yeah the slide to unlock needs an arrow. As mentioned, this us all great for existing users, but will be a barrier for new users. I understand that the whole point is that they are addressing the notion that users (and lets face it, there are a LOT of users of iOS) no longer need the same 'training', but you do need some basic discoverability and informative cues.
Also 'slide' us now a misnomer - you're not sliding anything! It's more like swipe to unlock. Too bad they didn't patent that.
They just need an arrow head that moves with the response. Like the rest of their buttonless buttons. Seriously - that slide to unlock button was one if the hallmark features of iPhone. It is often the first introduction to iOS, setting up the rest of the UI, and it was the first thing Steve jobs showed in the unveil.
In thus vein, I guess the removal if the button IS indicative if the rest if the UI, but there needs to be some 1:1 response as you slide. Wait, is there? Do the words disappear under your swipe as you slide?
Edit: oh, disregard, I guess it does slide in response. The screen slides.
Meh, maybe it's ok then. The response might be enough to teach people. Like the screen rubber bands if you try up. But then, I suppose you should ditch the control centre arrow.
Nah, it really needs SOMETHING.