>VFP supports block scoop, the block is the whole function.

This is not what I would call block scope. It is function scope.

>I would not disagree having block scoop to IF - Case - For - Etc... Statements, but this would really break a lot of existing code.

Not if you introduce a new syntax, like braces or an VB-like "Option scope" at the top of the code block.

Ex.:
Without code block:

FOR I = 1 TO 10 
   LOCAL N && N has procedure scope although it was declared within a block. 
   N = I
ENDFOR

W = 10 ^ N    && N is still visible outside the block it is declared in

With code block:

FOR I = 1 TO 10
   {
      LOCAL N && N has block scope
      N = I
   }
ENDFOR

W = 10 ^ N    && Error: N is not visible outside the block it is declared in

>I don't agrree a new Sys() function would make it harder the code to read, i would put the SYS() call in the INIT of my MTDLL's base class and then forget about it.

What if I want to write a new class that will be used by different applications having different scope definition? I would have to go through the gymnastic of saving the current setting, change it to what I need and restore it back. This will clutter my code.

This may also break existing code in your global classes that your application call.