That, combined with e-ink displays on the keys, could be quite useful. (samsung is doing that on their new dual flip phone, the Alias 2, so that the keys display different legends based on which way you open the display)

In 7c it would have qwerty, in 7d it would have a 12 key arrangement (with any other necessary keys).

In fact, that would be an amazing thing for Nokia to do if they're not going to do a 5 row keyboard: have the keys use e-ink to change what they're displaying based on the current mode, that way there's no guessing about what you're really putting into that password field, etc.. Then you could even avoid having pop-up menus for special keys when the keyboard is deployed -- just adjust the keyboard display.

I just don't know what they key ergonomics are like with e-ink on the caps. Hopefully you can still make a decent key to put the e-ink on top of.