As far as I know, a 'turn and clam' screen-keyboard joint might not make the unit that much more expensive, and would not really delay much at all either. Or allowing the Pandora's screen to completely swing over to the back (so that the 'top' side would be the screen, whereas the 'bottom' side would be keyboard/gaming controls).. Add a little hard-cover outer shell that goes over the keyboard/gaming controls and you have yourself a cheap and nice tablet Pandora.
See:
Also, a 'second edition' Pandora WITH tablet abilities has pretty severe implications on software. Least impact it'd have is lots of people screaming to the developers, asking for tablet-enabled controls...
Basically, what I'm saying is that if it should make the Pandora only 10 euros more expensive, and delay the Pandora by a month or so, it's *TOTALLY* worth it, and it will *TOTALLY* sell a *LOT* more (iPod peoples, etc.) and hence be something to at least put some thought into...