Consider this; two years ago when we were still waiting for SHIII and playing SHII, someonestarted a thread titled "Why SHI Is Still King". There are still a lot of people playing that 10-year-old sim, and a dedicated group of gamers who still play Pacific Thunder, which is a WAW-type online campaign using SHI.
There are a huge number of Americans who grew up watching movies like Run
Silent, Run Deep and still love to recreate that feeling, plus quite a few others who just want the variety.
Bet it sells as well or better than SHIII.