When you think about it, there's not a lot of fresh ground to trod in wargaming.
Just about every war anybody heard of -- and many that no one heard of -- has been done. Every level of command from private to field marshal is covered. Every era from the neolithic to interstellar is depicted.
So 1805: Sea of Glory is quite a remarkable design achievement. I won't say that strategic warfare in the age of sail is entirely untouched, but I think 1805: Sea of Glory is the first real serious wargame to attempt the topic. I'm looking forward to seeing how it plays in practice, but if it works as well as it appears it may this may open up a whole new genre of wargames. Evidently the next campaign that will be covered in 1798, but one can easily imagine games covering Suffren in the Indian Ocean and operations off the American Coast from the Revolution.
And one rich area for exploration would be the Anglo-Dutch Wars, which have been barely covered at all, largely because they don't have a lot of tactical interest and tactical games were the only age of sail games until now.