GoHaRu.com provides history and technical characteristics of E-50 Standardpanzer, new tank upcoming within World of Tanks.
When designed during WWII, E-50 was planned as a standard medium tank to replace Panther and Tiger I and the derivatives of these tanks.
"The Entwicklung series, more commonly known as the E-series, was a late-World War II attempt by Germany to produce a standardized series of tank designs. Standard designs in six different weight classes were to be created, from which several specialized variants were to be developed. This was necessitated by the extremely complex tank designs that had resulted in poor production rates and mechanical unreliability. The E-series designs were simpler, cheaper to produce and more efficient than their predecessors, however their design involved only modest improvements in armor and firepower over the designs they were intended to replace, such as the Hetzer, Panther G or Tiger II, and as such, they represent the eclipse of German armored vehicle design by tanks such as the American M46 Patton, the British Centurion Mk 5/2 and Soviet T-54 tanks, which would have been the Entwicklung Series' contemporaries and likely opponents."