Only found out quite recently about Ter Stegen myself, looks like a fine young goalkeeper. It´s becoming more and more obvious by the day that the next decade of football will belong to Spain and Germany.
Ter Stegen was the German goalie of the U17 team in 2009, when Germany won all the U (17/19/21) Championship in the same year. When Mönchengladbach played a half season with a goalie that cost them many many points (more points than Valdes costs Barcelona), he was promoted to #1 goalie and was really impressing. This season he had some problems, he let some goals through he defended in the two years before, but he's pulling out himself and improving again. He is a very fast learner and sooner or later he will end up at a huge club outside Germany. The big clubs are very aware of his qualities.
Yeah, I think that if ManU fans are writing off De Gea already, they are going to regret it. The guy has a lot of upside. Besides, next to (perhaps) Ter Stege I don´t see anyone who could handily fill the shoes of ManU 1st goalie.
If the ManU fans chase De Gea away they will sit in two years in front of the tv and think "why didn't he show that in our dress?" David is a goalie with great potential, and I'm very sure the coaches at ManU are working hard with him to improve his control of the box and the control at crosses.
Mou has more of a chance to leave Madrid than Iker