Samsung's new GALAXY S 4 has some pretty big shoes to fill. Destined to replace the most popular smartphone on the planet and the best selling Android smartphone to date, the Galaxy S III. With more than 50 million sold the GS3 was very popular, and with good reason. Can Samsung's new flagship remain the smartphone King? While it looks very similar, there's tons of differences. Samsung expects to sell nearly 100m of their new smartphone so read on to find out what it's all about.