Well we know it's coming, but maybe it's not too late to put a hand up and ask for some things to be included that may not yet be. I've thought about all the naval games I've played, some complex and some simple and tried to list many of the facets they have covered. Some were so complex they were a pain to play, I think SOG would be developed to err on the less complex (to make it more accessible to people) even though it will be more difficult than WOG..

So to start the ball rolling on discussion of features you might (or might not!) like here's a list of the top of my head..

Gunnery
Double shot, chain shot, grape shot, gunnery accuracy and rate of fire linked to crew quality, aimed fire (mast vs hull), bonus for carronades vs crew

Sailing
variation of ships sailing performance dependent on ship type, nation and attitude to the wind, penalties for ships that have not be in dock for years, coastal sailing (shoals, lee shore etc), "cutting out" battles, gunnery limitations with high seas (lower ports closed), drift, towing, ship formations, anchoring, wind changes of direction and strength

Battles
Grappling, fouling, collisions, boarding, ship damage effects to masts & hull and crew, explosions, fires, loss of rudder, command control and chain of command, night battles, fixed fortifications, surrender and prizes

Other stuff
Promotions (sort of like aces)