News broke over the weekend that Bumblebee's success at finding an audience has led to early development on a follow-up. The move comes before the movie has even finished its box office run. It's still currently in plenty of domestic and worldwide movie theaters (it's #1 in China!) and is even set to premiere in Japan coming up in March; Japan will be the last country the movie debuts in. So, it certainly hasn't reached the end of its shelf life yet.