Marvel now churns out two films a year, and is looking to start knocking out three per year by 2017; by comparison, there have been five X-Men movies since the year 2000 (not counting the Wolverine spin-offs). Obviously, more preparation for a movie is a safer bet than less, and a shorter development time is likely a big factor in why some Marvel movies feel so rushed and slight. Iron Man 2 and Thor 2 are particular offenders, but Age Of Ultron could have benefited from a longer development time to simplify that stacked story. The X-Men movies could soon become part of the modern blockbuster machine, and audiences could be looking at several X-films released year on year and built to satisfy a release date, much like MCU movies. As yet, that hasn't been the case. It's meant more attention paid to pre-production, and to getting the script right before committing to a deadline. As good as the MCU has been, it could benefit from a bit more love and care; currently, the tight schedule doesn't allow much creative wiggle-room.