You are waiting for more borg and romulans? Are you interested in a new enemy of the federation to appear or have another re-encounter like the cardassians?
Sentient AIs seem to be a lot less common and less powerful computationally in Fed space
Are they really rare, or are we seeing a universe shaped by and through the eyes of a civilization predisposed to deny and destroy them? Apart from the Doctor and Moriarty, how many others were simply shut off? How many beings like the exocomps were wiped when they "malfunctioned"? How many sentient computers are locked away in the Daystrom Institute, never to see the light of day?