20 Nov
2008
20 Nov
'08
8:05 p.m.
Making it reserved wouldn't be compatible. What could be done is perhaps to make it deprecated as an identifier, as a sort of preparation for making it reserved later.
If it comes to that, I'd like to do the same thing with "weak". There are probably more modifiers that have been up for discussion at one point or another, but I can't remember.