I was wondering when they would release it and what it would consist of. And its a doozy. In summary:
5x Experience gain on first win, all
consumables equipment (thanks BlueFletch) and training/retraining 50% off.
Tier 8 premium tanks: 15% discount to purchase
Tier 8 tanks: %30 credit income increase, %30 discount to purchase
Tier 7 SPG: same
Tier 5 medium and heavy tanks: 100% credit income increase
Tier 5 light tanks and SPGs: 50% credit income increase
Gift Shop Packages: The return of the KV-5 and the Type-62, as well as some hefty discounts (only $85 for a year of premium status)
All this starts at 6:30 AM Pacific time Friday*. Remember that because of the way the server resets happen in the evening here in North America, if you can skip playing Thursday evening and instead play in the afternoon/day on Friday, that will get you an extra 5x bonus (Friday before reset, Friday, Saturday, Sunday).
* Except the Gift Shop packages, which for some reason start Thursday night (11pm Pacific) and run to Saturday night (11pm Pacific)!