RX110, RX120, RX200 (others have suggested similar I'm sure)

I'm not that familiar with the Sony range, but I would assume the key differentiater between the NEX and Cyber-shot lines is removable versus fixed lens.  If that is the case, then I don't think a built-in EVF is precluded from any additional RX models.

I am really attracted to the RX100 as an alternative when I don't need to carry my DSLR, but I'm just not convinced I would be happy not having a viewfinder.  I currently have a Panasonic G3 which has an EVF, but this camera+kit lens combo is still too big and I really don't need the facility to change lenses for this type of use.

I would think a similar built-in EVF to the NEX could be fitted with only a minimal size increase.  I wouldn't want it to be the detachable bolt-on type as this would spoil the pocketability when fitted and be too fiddly to keep taking on and off - and I would probably lose it or forget to take it with me!  In any case, I think one of the key attractions of this type of camera is that it is a fully integrated one-piece device with no add-ons needed or offered.

Fred