I think if Ubisoft had released the SDK for SHIII then some things could have been very different.
With SH4, it was the Devs who pushed for a U Boat expansion pack. They wanted it as a free download, but the money men had other ideas. When you look at the work done by Leo Vampire, kriller 2, and many others currently modding for this game, I think the next 12 months will be exciting for SH4.