Case insensitivity is pretty Anglocentric. Much more interesting would be keyboard layout insensitivity. As an Israeli developer, if my password is, say, asdf, then from a usability viewpoint it would do me wonders if שדגכ would also be accepted, as I'll be writing something in Hebrew, switch to a different page, click a link that brings me to a login page where my username is saved, whoops just entered my password on the Hebrew layout by accident.

Reporting caps lock usage and not also keyboard layout usage is a pretty bad usability hole IMO.