Currently, Wikipedia article names are "case sensitive, but first character must be a capital".
This isn't optimal, because: * very rarely two things have the same name, only different capitalization * there is significant group of names thot should be all-lower-case, like many Unix programs
Fully case sensitive system also wouldn't be optimal. While it would allow all-lower-case names, it would force many links to be written as [[Foo|foo]], what would be an unnecessary burder.
So I propose a switch to "case insensitive but case preserving" system at some point, just like file names on Microsoft Windows.