None of the issues he wants to get "solved" have ever been an issue to me.
Taking away _GET, _POST and _SERVER would introduce issues.
The direction I want to see PHP going in is continued improvements in consistency. Stuff like turning all those fatal errors into runtime exceptions. And yes, making all string functions Unicode.
I get that the solution he proposed is different, and also reasonably sane, but isn't this basically what magic quotes did? Now that that nightmare is finally over, I'm not too keen on reliving it again.
The real world still has and probably always will have a lot of text in other encodings - Latin-1, Shift-JIS, heck even things like GSM03.38.
I like how Ruby handles it - every string has an encoding attached, and manipulations with non-compatible encodings will complain.
I don't want to have to flag every string as unicode. It is pointless as they already are all unicode, and it is not that bad to know the very small number times where php's binary functions don't work (e.g. substr, regex in certain cases).
That's a good point I hadn't thought about - processing binary files. I guess what I really want is a "texual string" class that you can trust. The problem right now are the inconsistent "mb_" functions that you sometimes have to use, don't always exist, and aren't always 1:1 mappings.