I would love a backlit keyboard, but I would like it to have white keys.
The issue is that when it's light, black keys just don't look right to me. However, when it's dark, the contrast between the white keys and the bright light on the letters might not be enough to make the keys stand out.
Basically, I love the look of the current keyboards and don't want that to change. But I want them backlit, too. Ugh. This is hard. Probably why they haven't done it yet.