The Navy is full of smart, strong and brave men and women.
Provides long-range, heavy artilery fire for land and amphibious units
Provides forward operations and launch point for aircraft
Transports those damned Marines
And need I mention the SEALs and SWCCs?
Their role in combat operations will likely only continue to increase as everyone loves a "clean" air war. However, because they do not have a true ground force anymore they are not self-sufficient and must work very closely with the Army/Marines during combat operations.