PS3 12 GB Sold Out at Major Retailers Online. Possible Sign of an E3 Announcement?

[fluky-nintendy]

V-r0cK said:
My first reaction is that maybe the 12gb PS3 aren't really selling so they just sell off what they have and stopped production for it.

But now im interested in the hopes of an even slimmer PS3 or a PS3 add-on to the PS4.

Bolded: how would that work?