Oooh, a chance to rant about bad ideas:
Control-W vs. Control-Q in firefox. The difference between close tab and close Firefox? Quite large. Which is why they're next to each other on the keyboard, of course. Not to mention, how often does one even want C-Q? Why does it even have a shortcut, isn't Alt-F, Q enough?
One of my requirements for an e16 theme (an X11 window manager) is that close window be on the opposite side as minimize/maximize/etc. Mac OS did this right, through 9.x; no idea (other than brain damage) they changed it in OS X. Oh, and made them color coded only (except on hover), just to show what Apple thinks of the colorblind. Microsoft hasn't managed to get this one right yet (but at least theirs aren't color only).
Putting close buttons on each tab, that was a great Firefox idea. Especially when tabs get small. Thankfully, can be disabled (is it off by default now? not sure).
The caps lock key, a feature never used except accidentally, gets a better spot on the keyboard than Control (and maybe even better than shift...). Fixable in software, thankfully.
Braindead keyboards with extra-large backspace or return keys, eating into where the other one and the pipe key should be.
And finally... Many UPSes (many APC UPSes, also many other brands) that use the power button as a test button. Release it too quickly, OOPS, just turned off the power. Press it longer for the test. Exactly the opposite of a PC power button (short press = software action, like safe shutdown or hibernate, long = bios override to cut power) and exactly the opposite of sanity. With UPSes you press the eject seat button for 4s to turn on the radio.