Two things:

1.  "Over the top" ultimate techs.  When I say "over the top," I don't mean imbalanced or OP.  I simply mean something "larger than life," something that gets blood pumping to the penis more than a new ship type or ability or whatever.

EXAMPLE:  Vasari ultimate techs.  First one allows phase jumping starbases.  Second one removes constraints on the number of starbases allowed in a gravity well, so that the vasari could actually phase jump several starbases into the same target grav well.

(I can already hear people screaming over this proposal, but again, there is no such thing as imbalanced or OP by definition.  Simply give the other sides the means to properly counter such beasts, and give the other sides similar cool and powerful ultimate techs.)

2.  Balance.  As old-timers know, this game was never properly balanced.  I would like to see more of a commitment from the devs to balancing this upcoming version of the game.  I own all versions of the game, but will not be buying this expansion until after it is released and I see what level of support in terms of balancing the devs give to it.  It is ridiculous that lrm spam is still dominant years after release, cap ships have issues, etc.