C'mon people! It's 2009!!
Where have you all been in the last decade?
If Apple wanted to shoot a commercial for the new iTablet (whatever they decided to call it), all they would have to do is have actors ooh and aah over a greenscreen-painted, external dimensions accurate prop with registration +'s all over it. Everyone on the set could be snapping off pics with their phone cams all day with nothing decent to show on Facebook/MySpace/MacRumors, etc. No need for NDA's, except maybe for dialog content, which is not nearly as sexy to feed rumors with than the ubiquitous "hasty and blurry elevator pic" seems to be.
In post production, the final computer model of the iTab could be added easily. When shooting, all of the lighting and camera angle info would be recorded and emulated in the CGI. If they alter the look of everything to make it retro 40's (maybe with film grain or altered color schemes), you'd never, ever be able to tell that it wasn't actually present during the shoot.
Nearly every computer commercial posts the disclaimer "screen images simulated." In this case, the entire unit would be simulated.
Nice thing about this approach is that any last minute design changes could be incorporated into the commercial without a reshoot.