16 cores on AM3+ or even 12 for that matter wont happen because AMD would have to do specially new die.
Thuban happened only because lisbon happened first.
And the new BD2 dies with more cores are going to be too different to implement on am3+ (integrated pcie etc).
MCM solution would need dedicated G34 single socket mobo (which no way in hell would cost 5mil as its all there), but AMD seems not interested in high end market right now.
It looks like AM3+ will be a short spanned socket like 1155 1156 intel ones.