Originally cameo appearances were planned in the film for Namor the Sub-Mariner, the Prince of Atlantis, but this was scrapped.
Originally cameo appearances were also planned for James Logan Howlett (Wolverine) and Erik Lensherr (Magneto), who were present during World War II (Logan was a soldier and Lensherr was a prisoner of war). These cameos were scrapped due to rights issues.