I want Connor Trinneer standing on a London street corner holding a cardboard sign saying "I didn't die"
Or maybe Matt Winston hidden in the background, like one of the Observers on
Fringe. It'd certainly generate a lot of speculation.
Seriously, though...
It could be argued that the Klingon helmets in
Into Darkness (and the deleted scenes of
Star Trek) are a big
Enterprise reference themselves. They were supposedly conceived because JJ and co. weren't sure originally if to have bumpy-headed Klingons or TOS-style smooth ones.
In
Into Darkness we will see a few Klingons unmasked (they have TNG-style bumps), but not all. So the backstory of "Affliction"/"Divergence", where a Klingon colony world but not the entire Empire was infected with the Augment virus won't be ignored or contradicted.