From September 1, 2015 until September 14, 2015 the next "On Track" for the NA server will be the MAUS according to RigorMortis_ :
T-25 will be the Premium tank reward, its a decent tank if you dont have it but for those who already do I feel sorry for the "No more Gold compensation" changes. The reactions I gathered from you, the event should be called "Off Track" from now on. *Smirk*
Note: Will be posting the discounts once they appear.